81452920 has 16 divisors (see below), whose sum is σ = 183269160. Its totient is φ = 32581152.

The previous prime is 81452911. The next prime is 81452951. The reversal of 81452920 is 2925418.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1018122 + ... + 1018201.

Almost surely, 2^81452920 is an apocalyptic number.

It is an amenable number.

81452920 is an abundant number, since it is smaller than the sum of its proper divisors (101816240).

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

81452920 is a wasteful number, since it uses less digits than its factorization.

81452920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2036334 (or 2036330 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 81452920 is about 9025.1271459188. The cubic root of 81452920 is about 433.4798216115.

The spelling of 81452920 in words is "eighty-one million, four hundred fifty-two thousand, nine hundred twenty".