81814560 has 48 divisors (see below), whose sum is σ = 257717376. Its totient is φ = 21817088.

The previous prime is 81814547. The next prime is 81814613. The reversal of 81814560 is 6541818.

It is a tau number, because it is divible by the number of its divisors (48).

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

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, 84744 + ... + 85703.

It is an arithmetic number, because the mean of its divisors is an integer number (5369112).

Almost surely, 2^81814560 is an apocalyptic number.

81814560 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81814560 is an abundant number, since it is smaller than the sum of its proper divisors (175902816).

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

81814560 is a wasteful number, since it uses less digits than its factorization.

81814560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170465 (or 170457 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 33.

The square root of 81814560 is about 9045.1401315845. The cubic root of 81814560 is about 434.1204051948.

The spelling of 81814560 in words is "eighty-one million, eight hundred fourteen thousand, five hundred sixty".