81904662 has 32 divisors (see below), whose sum is σ = 208012800. Its totient is φ = 23401224.

The previous prime is 81904661. The next prime is 81904681. The reversal of 81904662 is 26640918.

81904662 is a `hidden beast` number, since 8 + 190 + 466 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81904661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 107962 + ... + 108717.

It is an arithmetic number, because the mean of its divisors is an integer number (6500400).

Almost surely, 2^81904662 is an apocalyptic number.

81904662 is an abundant number, since it is smaller than the sum of its proper divisors (126108138).

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

81904662 is a wasteful number, since it uses less digits than its factorization.

81904662 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216697 (or 216691 counting only the distinct ones).

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

The square root of 81904662 is about 9050.1194467256. The cubic root of 81904662 is about 434.2797116656.

The spelling of 81904662 in words is "eighty-one million, nine hundred four thousand, six hundred sixty-two".