81542904 has 16 divisors (see below), whose sum is σ = 203857320. Its totient is φ = 27180960.

The previous prime is 81542893. The next prime is 81542911. The reversal of 81542904 is 40924518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1698787 + ... + 1698834.

Almost surely, 2^81542904 is an apocalyptic number.

It is an amenable number.

81542904 is an abundant number, since it is smaller than the sum of its proper divisors (122314416).

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

81542904 is a wasteful number, since it uses less digits than its factorization.

81542904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3397630 (or 3397626 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 81542904 is about 9030.1109627734. The cubic root of 81542904 is about 433.6393898349.

The spelling of 81542904 in words is "eighty-one million, five hundred forty-two thousand, nine hundred four".