51612640 has 48 divisors (see below), whose sum is σ = 122623200. Its totient is φ = 20528640.

The previous prime is 51612623. The next prime is 51612653. The reversal of 51612640 is 4621615.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31030 + ... + 32650.

It is an arithmetic number, because the mean of its divisors is an integer number (2554650).

Almost surely, 2^51612640 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 51612640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (61311600).

51612640 is an abundant number, since it is smaller than the sum of its proper divisors (71010560).

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

51612640 is a wasteful number, since it uses less digits than its factorization.

51612640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1835 (or 1827 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 51612640 is about 7184.1937613068. The cubic root of 51612640 is about 372.3219935347.

Subtracting from 51612640 its reverse (4621615), we obtain a square (46991025 = 6855²).

The spelling of 51612640 in words is "fifty-one million, six hundred twelve thousand, six hundred forty".