400648782861369 has 81 divisors (see below), whose sum is σ = 677853376382637. Its totient is φ = 227370088266048.

The previous prime is 400648782861329. The next prime is 400648782861401. The reversal of 400648782861369 is 963168287846004.

The square root of 400648782861369 is 20016213.

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

400648782861369 is a `hidden beast` number, since 4 + 0 + 0 + 6 + 487 + 8 + 2 + 8 + 6 + 136 + 9 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 328644868959225 + 72003913902144 = 18128565^2 + 8485512^2 .

It is not a de Polignac number, because 400648782861369 - 2¹⁵ = 400648782828601 is a prime.

It is a super-2 number, since 2×400648782861369² (a number of 30 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 400648782861297 and 400648782861306.

It is not an unprimeable number, because it can be changed into a prime (400648782861329) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 62630727279 + ... + 62630733675.

Almost surely, 2^{400648782861369} is an apocalyptic number.

400648782861369 is a gapful number since it is divisible by the number (49) formed by its first and last digit.

400648782861369 is the 20016213-rd square number.

400648782861369 is the 10008107-th centered octagonal number.

It is an amenable number.

400648782861369 is a deficient number, since it is larger than the sum of its proper divisors (277204593521268).

400648782861369 is an frugal number, since it uses more digits than its factorization.

400648782861369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13112 (or 6556 counting only the distinct ones).

The product of its (nonzero) digits is 668860416, while the sum is 72.

The spelling of 400648782861369 in words is "four hundred trillion, six hundred forty-eight billion, seven hundred eighty-two million, eight hundred sixty-one thousand, three hundred sixty-nine".