55981992 has 64 divisors (see below), whose sum is σ = 155597760. Its totient is φ = 16640000.

The previous prime is 55981967. The next prime is 55982011. The reversal of 55981992 is 29918955.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11992 + ... + 15992.

It is an arithmetic number, because the mean of its divisors is an integer number (2431215).

Almost surely, 2^55981992 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55981992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77798880).

55981992 is an abundant number, since it is smaller than the sum of its proper divisors (99615768).

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

55981992 is a wasteful number, since it uses less digits than its factorization.

55981992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4074 (or 4070 counting only the distinct ones).

The product of its digits is 291600, while the sum is 48.

The square root of 55981992 is about 7482.1114666917. Note that the first 3 decimals coincide. The cubic root of 55981992 is about 382.5452225570.

The spelling of 55981992 in words is "fifty-five million, nine hundred eighty-one thousand, nine hundred ninety-two".