51990320 has 20 divisors (see below), whose sum is σ = 120877680. Its totient is φ = 20796096.

The previous prime is 51990307. The next prime is 51990343. The reversal of 51990320 is 2309915.

It is a tau number, because it is divible by the number of its divisors (20).

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, 324860 + ... + 325019.

It is an arithmetic number, because the mean of its divisors is an integer number (6043884).

Almost surely, 2^51990320 is an apocalyptic number.

It is an amenable number.

51990320 is an abundant number, since it is smaller than the sum of its proper divisors (68887360).

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

51990320 is a wasteful number, since it uses less digits than its factorization.

51990320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649892 (or 649886 counting only the distinct ones).

The product of its (nonzero) digits is 2430, while the sum is 29.

The square root of 51990320 is about 7210.4313324516. The cubic root of 51990320 is about 373.2279535342.

The spelling of 51990320 in words is "fifty-one million, nine hundred ninety thousand, three hundred twenty".