51185520 has 120 divisors (see below), whose sum is σ = 178332336. Its totient is φ = 13644288.

The previous prime is 51185513. The next prime is 51185531. The reversal of 51185520 is 2558115.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18124 + ... + 20756.

Almost surely, 2^51185520 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 51185520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89166168).

51185520 is an abundant number, since it is smaller than the sum of its proper divisors (127146816).

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

51185520 is a wasteful number, since it uses less digits than its factorization.

51185520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2661 (or 2643 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 27.

The square root of 51185520 is about 7154.4056356905. The cubic root of 51185520 is about 371.2920980727.

The spelling of 51185520 in words is "fifty-one million, one hundred eighty-five thousand, five hundred twenty".