81608364 has 48 divisors (see below), whose sum is σ = 224028000. Its totient is φ = 25602048.

The previous prime is 81608357. The next prime is 81608377. The reversal of 81608364 is 46380618.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

81608364 is a modest number, since divided by 8364 gives 816 as remainder.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20389 + ... + 24060.

It is an arithmetic number, because the mean of its divisors is an integer number (4667250).

Almost surely, 2^81608364 is an apocalyptic number.

It is an amenable number.

81608364 is an abundant number, since it is smaller than the sum of its proper divisors (142419636).

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

81608364 is a wasteful number, since it uses less digits than its factorization.

81608364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44479 (or 44471 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 81608364 is about 9033.7347758278. The cubic root of 81608364 is about 433.7553960135.

The spelling of 81608364 in words is "eighty-one million, six hundred eight thousand, three hundred sixty-four".