81220264 has 16 divisors (see below), whose sum is σ = 152460000. Its totient is φ = 40564272.

The previous prime is 81220259. The next prime is 81220273. The reversal of 81220264 is 46202218.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2487 + ... + 12985.

It is an arithmetic number, because the mean of its divisors is an integer number (9528750).

Almost surely, 2^81220264 is an apocalyptic number.

It is an amenable number.

81220264 is a deficient number, since it is larger than the sum of its proper divisors (71239736).

81220264 is a wasteful number, since it uses less digits than its factorization.

81220264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11472 (or 11468 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 81220264 is about 9012.2285812112. The cubic root of 81220264 is about 433.0667083032.

The spelling of 81220264 in words is "eighty-one million, two hundred twenty thousand, two hundred sixty-four".