81960172 has 12 divisors (see below), whose sum is σ = 163920400. Its totient is φ = 35125776.

The previous prime is 81960163. The next prime is 81960223. The reversal of 81960172 is 27106918.

It is a happy number.

81960172 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1463547 + ... + 1463602.

Almost surely, 2^81960172 is an apocalyptic number.

It is an amenable number.

81960172 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.

81960172 is a wasteful number, since it uses less digits than its factorization.

81960172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2927160 (or 2927158 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 81960172 is about 9053.1857376285. The cubic root of 81960172 is about 434.3777989710.

The spelling of 81960172 in words is "eighty-one million, nine hundred sixty thousand, one hundred seventy-two".