51215808 has 112 divisors (see below), whose sum is σ = 158008320. Its totient is φ = 14337024.

The previous prime is 51215803. The next prime is 51215809. The reversal of 51215808 is 80851215.

51215808 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (112).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51215803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70873 + ... + 71591.

Almost surely, 2^51215808 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 51215808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79004160).

51215808 is an abundant number, since it is smaller than the sum of its proper divisors (106792512).

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

51215808 is a wasteful number, since it uses less digits than its factorization.

51215808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 794 (or 784 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 30.

The square root of 51215808 is about 7156.5220603307. The cubic root of 51215808 is about 371.3653185047.

The spelling of 51215808 in words is "fifty-one million, two hundred fifteen thousand, eight hundred eight".