81841992 has 32 divisors (see below), whose sum is σ = 207962880. Its totient is φ = 26832960.

The previous prime is 81841967. The next prime is 81842003. The reversal of 81841992 is 29914818.

It is a super-2 number, since 2×81841992² = 13396223309056128, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26488 + ... + 29415.

It is an arithmetic number, because the mean of its divisors is an integer number (6498840).

Almost surely, 2^81841992 is an apocalyptic number.

It is an amenable number.

81841992 is an abundant number, since it is smaller than the sum of its proper divisors (126120888).

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

81841992 is a wasteful number, since it uses less digits than its factorization.

81841992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55973 (or 55969 counting only the distinct ones).

The product of its digits is 41472, while the sum is 42.

The square root of 81841992 is about 9046.6563989134. The cubic root of 81841992 is about 434.1689192173.

The spelling of 81841992 in words is "eighty-one million, eight hundred forty-one thousand, nine hundred ninety-two".