81312526939 has 8 divisors (see below), whose sum is σ = 97819581440. Its totient is φ = 66028217256.

The previous prime is 81312526907. The next prime is 81312526963. The reversal of 81312526939 is 93962521318.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81312526939 - 2⁵ = 81312526907 is a prime.

It is a super-2 number, since 2×81312526939² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81312526892 and 81312526901.

It is not an unprimeable number, because it can be changed into a prime (81312526739) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 305686059 + ... + 305686324.

It is an arithmetic number, because the mean of its divisors is an integer number (12227447680).

Almost surely, 2^81312526939 is an apocalyptic number.

81312526939 is a deficient number, since it is larger than the sum of its proper divisors (16507054501).

81312526939 is a wasteful number, since it uses less digits than its factorization.

81312526939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611372409.

The product of its digits is 699840, while the sum is 49.

The spelling of 81312526939 in words is "eighty-one billion, three hundred twelve million, five hundred twenty-six thousand, nine hundred thirty-nine".