81237930 has 16 divisors (see below), whose sum is σ = 194971104. Its totient is φ = 21663440.

The previous prime is 81237913. The next prime is 81237973. The reversal of 81237930 is 3973218.

It is a junction number, because it is equal to n+sod(n) for n = 81237891 and 81237900.

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, 1353936 + ... + 1353995.

It is an arithmetic number, because the mean of its divisors is an integer number (12185694).

Almost surely, 2^81237930 is an apocalyptic number.

81237930 is an abundant number, since it is smaller than the sum of its proper divisors (113733174).

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

81237930 is a wasteful number, since it uses less digits than its factorization.

81237930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2707941.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 81237930 is about 9013.2086406562. The cubic root of 81237930 is about 433.0981044165.

The spelling of 81237930 in words is "eighty-one million, two hundred thirty-seven thousand, nine hundred thirty".