81864032 has 12 divisors (see below), whose sum is σ = 161169876. Its totient is φ = 40932000.

The previous prime is 81864019. The next prime is 81864037. The reversal of 81864032 is 23046818.

It is a Harshad number since it is a multiple of its sum of digits (32), and also a Moran number because the ratio is a prime number: 2558251 = 81864032 / (8 + 1 + 8 + 6 + 4 + 0 + 3 + 2).

It is a self number, because there is not a number n which added to its sum of digits gives 81864032.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81864037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1279094 + ... + 1279157.

It is an arithmetic number, because the mean of its divisors is an integer number (13430823).

Almost surely, 2^81864032 is an apocalyptic number.

It is an amenable number.

81864032 is a deficient number, since it is larger than the sum of its proper divisors (79305844).

81864032 is a wasteful number, since it uses less digits than its factorization.

81864032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2558261 (or 2558253 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 81864032 is about 9047.8744465206. The cubic root of 81864032 is about 434.2078895303.

The spelling of 81864032 in words is "eighty-one million, eight hundred sixty-four thousand, thirty-two".