81462720 has 56 divisors (see below), whose sum is σ = 258647184. Its totient is φ = 21723136.

The previous prime is 81462707. The next prime is 81462727. The reversal of 81462720 is 2726418.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81462727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41469 + ... + 43388.

Almost surely, 2^81462720 is an apocalyptic number.

81462720 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81462720 is an abundant number, since it is smaller than the sum of its proper divisors (177184464).

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

81462720 is a wasteful number, since it uses less digits than its factorization.

81462720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84877 (or 84867 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 81462720 is about 9025.6700582284. The cubic root of 81462720 is about 433.4972056083.

The spelling of 81462720 in words is "eighty-one million, four hundred sixty-two thousand, seven hundred twenty".