81937492 has 48 divisors (see below), whose sum is σ = 177692032. Its totient is φ = 32192640.

The previous prime is 81937483. The next prime is 81937529. The reversal of 81937492 is 29473918.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58642 + ... + 60022.

Almost surely, 2^81937492 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81937492, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88846016).

81937492 is an abundant number, since it is smaller than the sum of its proper divisors (95754540).

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

81937492 is a wasteful number, since it uses less digits than its factorization.

81937492 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1568 (or 1566 counting only the distinct ones).

The product of its digits is 108864, while the sum is 43.

The square root of 81937492 is about 9051.9330532213. The cubic root of 81937492 is about 434.3377282997.

The spelling of 81937492 in words is "eighty-one million, nine hundred thirty-seven thousand, four hundred ninety-two".