7978698466281 has 63 divisors (see below), whose sum is σ = 12040954353589. Its totient is φ = 5284507640832.

The previous prime is 7978698466267. The next prime is 7978698466303. The reversal of 7978698466281 is 1826648968797.

The square root of 7978698466281 is 2824659.

It is a perfect power (a square), and thus also a powerful number.

7978698466281 is a `hidden beast` number, since 7 + 9 + 78 + 6 + 9 + 8 + 466 + 2 + 81 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 333384986025 + 7645313480256 = 577395^2 + 2765016^2 .

It is a de Polignac number, because none of the positive numbers 2^k-7978698466281 is a prime.

It is a super-2 number, since 2×7978698466281² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7978698466281.

It is not an unprimeable number, because it can be changed into a prime (7978698466681) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 17769929545 + ... + 17769929993.

Almost surely, 2^{7978698466281} is an apocalyptic number.

7978698466281 is the 2824659-th square number.

7978698466281 is the 1412330-th centered octagonal number.

It is an amenable number.

7978698466281 is a deficient number, since it is larger than the sum of its proper divisors (4062255887308).

7978698466281 is an frugal number, since it uses more digits than its factorization.

7978698466281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1382 (or 685 counting only the distinct ones).

The product of its digits is 3511517184, while the sum is 81.

Multiplying 7978698466281 by its sum of digits (81), we get a square (646274575768761 = 25421931²).

7978698466281 divided by its sum of digits (81) gives a square (98502450201 = 313851²).

The spelling of 7978698466281 in words is "seven trillion, nine hundred seventy-eight billion, six hundred ninety-eight million, four hundred sixty-six thousand, two hundred eighty-one".