51506784 has 144 divisors (see below), whose sum is σ = 173365920. Its totient is φ = 14192640.

The previous prime is 51506731. The next prime is 51506797. The reversal of 51506784 is 48760515.

51506784 is a `hidden beast` number, since 515 + 0 + 67 + 84 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

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 23 ways as a sum of consecutive naturals, for example, 58024 + ... + 58904.

It is an arithmetic number, because the mean of its divisors is an integer number (1203930).

Almost surely, 2^51506784 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 51506784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86682960).

51506784 is an abundant number, since it is smaller than the sum of its proper divisors (121859136).

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

51506784 is a wasteful number, since it uses less digits than its factorization.

51506784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 933 (or 922 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The square root of 51506784 is about 7176.8226953158. The cubic root of 51506784 is about 372.0672788477.

The spelling of 51506784 in words is "fifty-one million, five hundred six thousand, seven hundred eighty-four".