81407472 has 20 divisors (see below), whose sum is σ = 210302760. Its totient is φ = 27135808.

The previous prime is 81407449. The next prime is 81407477. The reversal of 81407472 is 27470418.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81407477) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 847947 + ... + 848042.

It is an arithmetic number, because the mean of its divisors is an integer number (10515138).

Almost surely, 2^81407472 is an apocalyptic number.

It is an amenable number.

81407472 is an abundant number, since it is smaller than the sum of its proper divisors (128895288).

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

81407472 is a wasteful number, since it uses less digits than its factorization.

81407472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1696000 (or 1695994 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 33.

The square root of 81407472 is about 9022.6089353357. The cubic root of 81407472 is about 433.3991842069.

The spelling of 81407472 in words is "eighty-one million, four hundred seven thousand, four hundred seventy-two".