51362640 has 320 divisors, whose sum is σ = 209510400. Its totient is φ = 11321856.

The previous prime is 51362621. The next prime is 51362659. The reversal of 51362640 is 4626315.

51362640 is a `hidden beast` number, since 5 + 13 + 6 + 2 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (51362621) and next prime (51362659).

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 650121 + ... + 650199.

It is an arithmetic number, because the mean of its divisors is an integer number (654720).

Almost surely, 2^51362640 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 51362640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104755200).

51362640 is an abundant number, since it is smaller than the sum of its proper divisors (158147760).

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

51362640 is a wasteful number, since it uses less digits than its factorization.

51362640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151 (or 139 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 51362640 is about 7166.7733325395. The cubic root of 51362640 is about 371.7198723547.

Adding to 51362640 its reverse (4626315), we get a palindrome (55988955).

It can be divided in two parts, 5136 and 2640, that added together give a 5-th power (7776 = 6⁵).

The spelling of 51362640 in words is "fifty-one million, three hundred sixty-two thousand, six hundred forty".