81372856 has 16 divisors (see below), whose sum is σ = 156123000. Its totient is φ = 39740064.

The previous prime is 81372833. The next prime is 81372857. The reversal of 81372856 is 65827318.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81372857) 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, 117931 + ... + 118618.

Almost surely, 2^81372856 is an apocalyptic number.

81372856 is a gapful number since it is divisible by the number (86) formed by its first and last digit.

It is an amenable number.

81372856 is a deficient number, since it is larger than the sum of its proper divisors (74750144).

81372856 is a wasteful number, since it uses less digits than its factorization.

81372856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236598 (or 236594 counting only the distinct ones).

The product of its digits is 80640, while the sum is 40.

The square root of 81372856 is about 9020.6904392070. The cubic root of 81372856 is about 433.3377456487.

It can be divided in two parts, 81372 and 856, that added together give a palindrome (82228).

The spelling of 81372856 in words is "eighty-one million, three hundred seventy-two thousand, eight hundred fifty-six".