81542082072 has 64 divisors (see below), whose sum is σ = 228397996800. Its totient is φ = 24041888640.

The previous prime is 81542082043. The next prime is 81542082073. The reversal of 81542082072 is 27028024518.

It is a super-2 number, since 2×81542082072² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81542082072.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81542082073) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4164172 + ... + 4183707.

It is an arithmetic number, because the mean of its divisors is an integer number (3568718700).

Almost surely, 2^81542082072 is an apocalyptic number.

It is an amenable number.

81542082072 is an abundant number, since it is smaller than the sum of its proper divisors (146855914728).

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

81542082072 is a wasteful number, since it uses less digits than its factorization.

81542082072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8347936 (or 8347932 counting only the distinct ones).

The product of its (nonzero) digits is 71680, while the sum is 39.

The spelling of 81542082072 in words is "eighty-one billion, five hundred forty-two million, eighty-two thousand, seventy-two".