81323892 has 48 divisors (see below), whose sum is σ = 227062080. Its totient is φ = 25022304.

The previous prime is 81323873. The next prime is 81323899. The reversal of 81323892 is 29832318.

It is a happy number.

It is a super-2 number, since 2×81323892² = 13227150820055328, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81323899) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27558 + ... + 30365.

It is an arithmetic number, because the mean of its divisors is an integer number (4730460).

Almost surely, 2^81323892 is an apocalyptic number.

It is an amenable number.

81323892 is an abundant number, since it is smaller than the sum of its proper divisors (145738188).

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

81323892 is a wasteful number, since it uses less digits than its factorization.

81323892 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57949 (or 57941 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 81323892 is about 9017.9760478724. The cubic root of 81323892 is about 433.2508116364.

It can be divided in two parts, 81323 and 892, that added together give a triangular number (82215 = T₄₀₅).

The spelling of 81323892 in words is "eighty-one million, three hundred twenty-three thousand, eight hundred ninety-two".