81137884 has 6 divisors (see below), whose sum is σ = 141991304. Its totient is φ = 40568940.

The previous prime is 81137879. The next prime is 81137897. The reversal of 81137884 is 48873118.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10142232 + ... + 10142239.

Almost surely, 2^81137884 is an apocalyptic number.

It is an amenable number.

81137884 is a deficient number, since it is larger than the sum of its proper divisors (60853420).

81137884 is a wasteful number, since it uses less digits than its factorization.

81137884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20284475 (or 20284473 counting only the distinct ones).

The product of its digits is 43008, while the sum is 40.

The square root of 81137884 is about 9007.6569650492. The cubic root of 81137884 is about 432.9202419646.

The spelling of 81137884 in words is "eighty-one million, one hundred thirty-seven thousand, eight hundred eighty-four".