51999216 has 20 divisors (see below), whose sum is σ = 134331432. Its totient is φ = 17333056.

The previous prime is 51999197. The next prime is 51999247. The reversal of 51999216 is 61299915.

It is a happy number.

51999216 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×51999216² = 5407836929229312, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 541611 + ... + 541706.

Almost surely, 2^51999216 is an apocalyptic number.

It is an amenable number.

51999216 is an abundant number, since it is smaller than the sum of its proper divisors (82332216).

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

51999216 is a wasteful number, since it uses less digits than its factorization.

51999216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1083328 (or 1083322 counting only the distinct ones).

The product of its digits is 43740, while the sum is 42.

The square root of 51999216 is about 7211.0481901038. The cubic root of 51999216 is about 373.2492398462.

The spelling of 51999216 in words is "fifty-one million, nine hundred ninety-nine thousand, two hundred sixteen".