81606264 has 64 divisors (see below), whose sum is σ = 209744640. Its totient is φ = 26449920.

The previous prime is 81606253. The next prime is 81606269. The reversal of 81606264 is 46260618.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81606269) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 141144 + ... + 141720.

It is an arithmetic number, because the mean of its divisors is an integer number (3277260).

Almost surely, 2^81606264 is an apocalyptic number.

It is an amenable number.

81606264 is an abundant number, since it is smaller than the sum of its proper divisors (128138376).

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

81606264 is a wasteful number, since it uses less digits than its factorization.

81606264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 740 (or 736 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 81606264 is about 9033.6185440830. The cubic root of 81606264 is about 433.7516754220.

The spelling of 81606264 in words is "eighty-one million, six hundred six thousand, two hundred sixty-four".