81916464 has 40 divisors (see below), whose sum is σ = 241849600. Its totient is φ = 23404608.

The previous prime is 81916451. The next prime is 81916487. The reversal of 81916464 is 46461918.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 121564 + ... + 122235.

It is an arithmetic number, because the mean of its divisors is an integer number (6046240).

Almost surely, 2^81916464 is an apocalyptic number.

81916464 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

81916464 is an abundant number, since it is smaller than the sum of its proper divisors (159933136).

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

81916464 is a wasteful number, since it uses less digits than its factorization.

81916464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243817 (or 243811 counting only the distinct ones).

The product of its digits is 41472, while the sum is 39.

The square root of 81916464 is about 9050.7714588316. The cubic root of 81916464 is about 434.3005697497.

The spelling of 81916464 in words is "eighty-one million, nine hundred sixteen thousand, four hundred sixty-four".