51812640 has 144 divisors (see below), whose sum is σ = 192943296. Its totient is φ = 12556800.

The previous prime is 51812627. The next prime is 51812689. The reversal of 51812640 is 4621815.

51812640 is a `hidden beast` number, since 5 + 1 + 8 + 12 + 640 = 666.

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

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, 14205 + ... + 17475.

It is an arithmetic number, because the mean of its divisors is an integer number (1339884).

Almost surely, 2^51812640 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 51812640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96471648).

51812640 is an abundant number, since it is smaller than the sum of its proper divisors (141130656).

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

51812640 is a wasteful number, since it uses less digits than its factorization.

51812640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3303 (or 3292 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 51812640 is about 7198.0997492394. The cubic root of 51812640 is about 372.8022920402.

The spelling of 51812640 in words is "fifty-one million, eight hundred twelve thousand, six hundred forty".