51557688 has 256 divisors, whose sum is σ = 183321600. Its totient is φ = 13063680.

The previous prime is 51557663. The next prime is 51557699. The reversal of 51557688 is 88675515.

51557688 is a `hidden beast` number, since 515 + 57 + 6 + 88 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 845178 + ... + 845238.

It is an arithmetic number, because the mean of its divisors is an integer number (716100).

Almost surely, 2^51557688 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 51557688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91660800).

51557688 is an abundant number, since it is smaller than the sum of its proper divisors (131763912).

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

51557688 is a wasteful number, since it uses less digits than its factorization.

51557688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139 (or 129 counting only the distinct ones).

The product of its digits is 336000, while the sum is 45.

The square root of 51557688 is about 7180.3682356826. The cubic root of 51557688 is about 372.1898094826.

The spelling of 51557688 in words is "fifty-one million, five hundred fifty-seven thousand, six hundred eighty-eight".