51355920 has 240 divisors, whose sum is σ = 202540608. Its totient is φ = 10644480.

The previous prime is 51355919. The next prime is 51355939. The reversal of 51355920 is 2955315.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 129162 + ... + 129558.

Almost surely, 2^51355920 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 51355920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101270304).

51355920 is an abundant number, since it is smaller than the sum of its proper divisors (151184688).

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

51355920 is a wasteful number, since it uses less digits than its factorization.

51355920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438 (or 425 counting only the distinct ones).

The product of its (nonzero) digits is 6750, while the sum is 30.

The square root of 51355920 is about 7166.3044869723. The cubic root of 51355920 is about 371.7036603993.

The spelling of 51355920 in words is "fifty-one million, three hundred fifty-five thousand, nine hundred twenty".