51999872 has 64 divisors (see below), whose sum is σ = 114566400. Its totient is φ = 23384064.

The previous prime is 51999853. The next prime is 51999887. The reversal of 51999872 is 27899915.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 51999872.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49529 + ... + 50567.

It is an arithmetic number, because the mean of its divisors is an integer number (1790100).

Almost surely, 2^51999872 is an apocalyptic number.

51999872 is the 5888-th pentagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51999872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (57283200).

51999872 is an abundant number, since it is smaller than the sum of its proper divisors (62566528).

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

51999872 is a wasteful number, since it uses less digits than its factorization.

51999872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1093 (or 1081 counting only the distinct ones).

The product of its digits is 408240, while the sum is 50.

The square root of 51999872 is about 7211.0936757194. The cubic root of 51999872 is about 373.2508094241.

The spelling of 51999872 in words is "fifty-one million, nine hundred ninety-nine thousand, eight hundred seventy-two".