51805980 has 120 divisors (see below), whose sum is σ = 164534832. Its totient is φ = 13644288.

The previous prime is 51805979. The next prime is 51805993. The reversal of 51805980 is 8950815.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 182919 + ... + 183201.

Almost surely, 2^51805980 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 51805980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82267416).

51805980 is an abundant number, since it is smaller than the sum of its proper divisors (112728852).

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

51805980 is a wasteful number, since it uses less digits than its factorization.

51805980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417 (or 406 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 36.

The square root of 51805980 is about 7197.6371122751. The cubic root of 51805980 is about 372.7863180124.

The spelling of 51805980 in words is "fifty-one million, eight hundred five thousand, nine hundred eighty".