81138092 has 12 divisors (see below), whose sum is σ = 162276240. Its totient is φ = 34773456.

The previous prime is 81138091. The next prime is 81138103. The reversal of 81138092 is 29083118.

81138092 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (81138091) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1448867 + ... + 1448922.

It is an arithmetic number, because the mean of its divisors is an integer number (13523020).

Almost surely, 2^81138092 is an apocalyptic number.

It is an amenable number.

81138092 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81138092 is a wasteful number, since it uses less digits than its factorization.

81138092 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2897800 (or 2897798 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 81138092 is about 9007.6685107746. The cubic root of 81138092 is about 432.9206119001.

The spelling of 81138092 in words is "eighty-one million, one hundred thirty-eight thousand, ninety-two".