81972514 has 16 divisors (see below), whose sum is σ = 132641208. Its totient is φ = 37769472.

The previous prime is 81972511. The next prime is 81972563. The reversal of 81972514 is 41527918.

It can be written as a sum of positive squares in 4 ways, for example, as 66504025 + 15468489 = 8155^2 + 3933^2 .

It is not an unprimeable number, because it can be changed into a prime (81972511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15274 + ... + 19930.

Almost surely, 2^81972514 is an apocalyptic number.

81972514 is a deficient number, since it is larger than the sum of its proper divisors (50668694).

81972514 is a wasteful number, since it uses less digits than its factorization.

81972514 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5349.

The product of its digits is 20160, while the sum is 37.

The square root of 81972514 is about 9053.8673504752. The cubic root of 81972514 is about 434.3996015188.

The spelling of 81972514 in words is "eighty-one million, nine hundred seventy-two thousand, five hundred fourteen".