81933912 has 48 divisors (see below), whose sum is σ = 231557040. Its totient is φ = 26123328.

The previous prime is 81933911. The next prime is 81933937. The reversal of 81933912 is 21933918.

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

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81933911) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23083 + ... + 26394.

It is an arithmetic number, because the mean of its divisors is an integer number (4824105).

Almost surely, 2^81933912 is an apocalyptic number.

It is an amenable number.

81933912 is an abundant number, since it is smaller than the sum of its proper divisors (149623128).

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

81933912 is a wasteful number, since it uses less digits than its factorization.

81933912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49512 (or 49505 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 81933912 is about 9051.7353032443. The cubic root of 81933912 is about 434.3314025357.

The spelling of 81933912 in words is "eighty-one million, nine hundred thirty-three thousand, nine hundred twelve".