81642264 has 32 divisors (see below), whose sum is σ = 222661440. Its totient is φ = 24740000.

The previous prime is 81642257. The next prime is 81642283. The reversal of 81642264 is 46224618.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a nude number because it is divisible by every one of its digits.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 154362 + ... + 154889.

It is an arithmetic number, because the mean of its divisors is an integer number (6958170).

Almost surely, 2^81642264 is an apocalyptic number.

It is an amenable number.

81642264 is an abundant number, since it is smaller than the sum of its proper divisors (141019176).

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

81642264 is a wasteful number, since it uses less digits than its factorization.

81642264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309271 (or 309267 counting only the distinct ones).

The product of its digits is 18432, while the sum is 33.

The square root of 81642264 is about 9035.6108813959. The cubic root of 81642264 is about 433.8154481602.

The spelling of 81642264 in words is "eighty-one million, six hundred forty-two thousand, two hundred sixty-four".