81450972 has 36 divisors (see below), whose sum is σ = 207215736. Its totient is φ = 26975520.

The previous prime is 81450917. The next prime is 81450977. The reversal of 81450972 is 27905418.

81450972 is a `hidden beast` number, since 81 + 4 + 509 + 72 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81450977) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 1554 + ... + 12857.

Almost surely, 2^81450972 is an apocalyptic number.

It is an amenable number.

81450972 is an abundant number, since it is smaller than the sum of its proper divisors (125764764).

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

81450972 is a wasteful number, since it uses less digits than its factorization.

81450972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14578 (or 14573 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 81450972 is about 9025.0192243563. The cubic root of 81450972 is about 433.4763659325.

The spelling of 81450972 in words is "eighty-one million, four hundred fifty thousand, nine hundred seventy-two".