81572502 has 16 divisors (see below), whose sum is σ = 177976512. Its totient is φ = 24718920.

The previous prime is 81572497. The next prime is 81572527. The reversal of 81572502 is 20527518.

It is a super-5 number, since 5×81572502⁵ (a number of 41 digits) contains 55555 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81572502.

It is a congruent number.

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, 617908 + ... + 618039.

It is an arithmetic number, because the mean of its divisors is an integer number (11123532).

Almost surely, 2^81572502 is an apocalyptic number.

81572502 is an abundant number, since it is smaller than the sum of its proper divisors (96404010).

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

81572502 is a wasteful number, since it uses less digits than its factorization.

81572502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1235963.

The product of its (nonzero) digits is 5600, while the sum is 30.

The square root of 81572502 is about 9031.7496643784. The cubic root of 81572502 is about 433.6918501776.

The spelling of 81572502 in words is "eighty-one million, five hundred seventy-two thousand, five hundred two".