81600072 has 32 divisors (see below), whose sum is σ = 207852480. Its totient is φ = 26686400.

The previous prime is 81600053. The next prime is 81600073. The reversal of 81600072 is 27000618.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (81600073) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 30804 + ... + 33347.

It is an arithmetic number, because the mean of its divisors is an integer number (6495390).

Almost surely, 2^81600072 is an apocalyptic number.

It is an amenable number.

81600072 is an abundant number, since it is smaller than the sum of its proper divisors (126252408).

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

81600072 is a wasteful number, since it uses less digits than its factorization.

81600072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64213 (or 64209 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 81600072 is about 9033.2758177751. The cubic root of 81600072 is about 433.7407046208.

The spelling of 81600072 in words is "eighty-one million, six hundred thousand, seventy-two".