81933620 has 24 divisors (see below), whose sum is σ = 177612288. Its totient is φ = 31716000.

The previous prime is 81933583. The next prime is 81933623. The reversal of 81933620 is 2633918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81933623) 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, 65456 + ... + 66695.

It is an arithmetic number, because the mean of its divisors is an integer number (7400512).

Almost surely, 2^81933620 is an apocalyptic number.

It is an amenable number.

81933620 is an abundant number, since it is smaller than the sum of its proper divisors (95678668).

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

81933620 is a wasteful number, since it uses less digits than its factorization.

81933620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132191 (or 132189 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 81933620 is about 9051.7191737261. The cubic root of 81933620 is about 434.3308865714.

The spelling of 81933620 in words is "eighty-one million, nine hundred thirty-three thousand, six hundred twenty".