81937192 has 8 divisors (see below), whose sum is σ = 153632250. Its totient is φ = 40968592.

The previous prime is 81937189. The next prime is 81937211. The reversal of 81937192 is 29173918.

It can be written as a sum of positive squares in only one way, i.e., 47527236 + 34409956 = 6894^2 + 5866^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is an upside-down number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5121067 + ... + 5121082.

Almost surely, 2^81937192 is an apocalyptic number.

It is an amenable number.

81937192 is a deficient number, since it is larger than the sum of its proper divisors (71695058).

81937192 is a wasteful number, since it uses less digits than its factorization.

81937192 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10242155 (or 10242151 counting only the distinct ones).

The product of its digits is 27216, while the sum is 40.

The square root of 81937192 is about 9051.9164821600. The cubic root of 81937192 is about 434.3371982148.

The spelling of 81937192 in words is "eighty-one million, nine hundred thirty-seven thousand, one hundred ninety-two".