81377892 has 24 divisors (see below), whose sum is σ = 210980000. Its totient is φ = 27125928.

The previous prime is 81377873. The next prime is 81377897. The reversal of 81377892 is 29877318.

It is a super-2 number, since 2×81377892² = 13244722612727328, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81377897) 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, 376642 + ... + 376857.

Almost surely, 2^81377892 is an apocalyptic number.

It is an amenable number.

81377892 is an abundant number, since it is smaller than the sum of its proper divisors (129602108).

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

81377892 is a wasteful number, since it uses less digits than its factorization.

81377892 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 753512 (or 753504 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 81377892 is about 9020.9695709497. The cubic root of 81377892 is about 433.3466849272.

The spelling of 81377892 in words is "eighty-one million, three hundred seventy-seven thousand, eight hundred ninety-two".