81012690432 has 400 divisors, whose sum is σ = 248922661680. Its totient is φ = 26221805568.

The previous prime is 81012690391. The next prime is 81012690457. The reversal of 81012690432 is 23409621018.

81012690432 is a `hidden beast` number, since 8 + 10 + 126 + 90 + 432 = 666.

It is a super-2 number, since 2×81012690432² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 276493678 + ... + 276493970.

Almost surely, 2^81012690432 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81012690432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124461330840).

81012690432 is an abundant number, since it is smaller than the sum of its proper divisors (167909971248).

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

81012690432 is a wasteful number, since it uses less digits than its factorization.

81012690432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 495 (or 470 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The spelling of 81012690432 in words is "eighty-one billion, twelve million, six hundred ninety thousand, four hundred thirty-two".