81959960 has 32 divisors (see below), whose sum is σ = 185749200. Its totient is φ = 32545920.

The previous prime is 81959957. The next prime is 81959981. The reversal of 81959960 is 6995918.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1811 + ... + 12930.

Almost surely, 2^81959960 is an apocalyptic number.

It is an amenable number.

81959960 is an abundant number, since it is smaller than the sum of its proper divisors (103789240).

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

81959960 is a wasteful number, since it uses less digits than its factorization.

81959960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14891 (or 14887 counting only the distinct ones).

The product of its (nonzero) digits is 174960, while the sum is 47.

The square root of 81959960 is about 9053.1740290353. The cubic root of 81959960 is about 434.3774244469.

The spelling of 81959960 in words is "eighty-one million, nine hundred fifty-nine thousand, nine hundred sixty".