81312526938 has 16 divisors (see below), whose sum is σ = 162676932480. Its totient is φ = 27095529216.

The previous prime is 81312526907. The next prime is 81312526963. The reversal of 81312526938 is 83962521318.

It is a super-2 number, since 2×81312526938² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2141218 + ... + 2178861.

It is an arithmetic number, because the mean of its divisors is an integer number (10167308280).

Almost surely, 2^81312526938 is an apocalyptic number.

81312526938 is an abundant number, since it is smaller than the sum of its proper divisors (81364405542).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81312526938 is a wasteful number, since it uses less digits than its factorization.

81312526938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4323221.

The product of its digits is 622080, while the sum is 48.

The spelling of 81312526938 in words is "eighty-one billion, three hundred twelve million, five hundred twenty-six thousand, nine hundred thirty-eight".