81872456 has 32 divisors (see below), whose sum is σ = 160704000. Its totient is φ = 39029760.

The previous prime is 81872447. The next prime is 81872467. The reversal of 81872456 is 65427818.

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, 82121 + ... + 83111.

It is an arithmetic number, because the mean of its divisors is an integer number (5022000).

Almost surely, 2^81872456 is an apocalyptic number.

It is an amenable number.

81872456 is a deficient number, since it is larger than the sum of its proper divisors (78831544).

81872456 is a wasteful number, since it uses less digits than its factorization.

81872456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1469 (or 1465 counting only the distinct ones).

The product of its digits is 107520, while the sum is 41.

The square root of 81872456 is about 9048.3399582465. The cubic root of 81872456 is about 434.2227826880. Note that the first 3 decimals are identical.

It can be divided in two parts, 81872 and 456, that added together give a palindrome (82328).

The spelling of 81872456 in words is "eighty-one million, eight hundred seventy-two thousand, four hundred fifty-six".