81971124 has 24 divisors (see below), whose sum is σ = 191499840. Its totient is φ = 27290304.

The previous prime is 81971117. The next prime is 81971137. The reversal of 81971124 is 42117918.

It is a congruent number.

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, 7312 + ... + 14744.

It is an arithmetic number, because the mean of its divisors is an integer number (7979160).

Almost surely, 2^81971124 is an apocalyptic number.

It is an amenable number.

81971124 is an abundant number, since it is smaller than the sum of its proper divisors (109528716).

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

81971124 is a wasteful number, since it uses less digits than its factorization.

81971124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8359 (or 8357 counting only the distinct ones).

The product of its digits is 4032, while the sum is 33.

The square root of 81971124 is about 9053.7905873728. The cubic root of 81971124 is about 434.3971461476.

The spelling of 81971124 in words is "eighty-one million, nine hundred seventy-one thousand, one hundred twenty-four".