81805460 has 24 divisors (see below), whose sum is σ = 187409376. Its totient is φ = 29747360.

The previous prime is 81805429. The next prime is 81805487. The reversal of 81805460 is 6450818.

It is a congruent number.

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, 185702 + ... + 186141.

It is an arithmetic number, because the mean of its divisors is an integer number (7808724).

Almost surely, 2^81805460 is an apocalyptic number.

It is an amenable number.

81805460 is an abundant number, since it is smaller than the sum of its proper divisors (105603916).

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

81805460 is a wasteful number, since it uses less digits than its factorization.

81805460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 371863 (or 371861 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 81805460 is about 9044.6370850355. The cubic root of 81805460 is about 434.1043092735.

The spelling of 81805460 in words is "eighty-one million, eight hundred five thousand, four hundred sixty".