81010904 has 16 divisors (see below), whose sum is σ = 163579920. Its totient is φ = 37389600.

The previous prime is 81010903. The next prime is 81010907. The reversal of 81010904 is 40901018.

It is a self number, because there is not a number n which added to its sum of digits gives 81010904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81010903) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 389372 + ... + 389579.

It is an arithmetic number, because the mean of its divisors is an integer number (10223745).

Almost surely, 2^81010904 is an apocalyptic number.

It is an amenable number.

81010904 is an abundant number, since it is smaller than the sum of its proper divisors (82569016).

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

81010904 is a wasteful number, since it uses less digits than its factorization.

81010904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 778970 (or 778966 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 81010904 is about 9000.6057573921. The cubic root of 81010904 is about 432.6942853931.

The spelling of 81010904 in words is "eighty-one million, ten thousand, nine hundred four".