7938261985 has 4 divisors (see below), whose sum is σ = 9525914388. Its totient is φ = 6350609584.

The previous prime is 7938261973. The next prime is 7938262009. The reversal of 7938261985 is 5891628397.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5891628397 = 18119 ⋅325163.

It can be written as a sum of positive squares in 2 ways, for example, as 1222131681 + 6716130304 = 34959^2 + 81952^2 .

It is a cyclic number.

It is not a de Polignac number, because 7938261985 - 2⁹ = 7938261473 is a prime.

It is a super-2 number, since 2×7938261985² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 793826194 + ... + 793826203.

It is an arithmetic number, because the mean of its divisors is an integer number (2381478597).

Almost surely, 2^7938261985 is an apocalyptic number.

It is an amenable number.

7938261985 is a deficient number, since it is larger than the sum of its proper divisors (1587652403).

7938261985 is a wasteful number, since it uses less digits than its factorization.

7938261985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1587652402.

The product of its digits is 6531840, while the sum is 58.

The square root of 7938261985 is about 89096.9246663430. The cubic root of 7938261985 is about 1994.8418737198.

The spelling of 7938261985 in words is "seven billion, nine hundred thirty-eight million, two hundred sixty-one thousand, nine hundred eighty-five".