51613440 has 72 divisors (see below), whose sum is σ = 164852688. Its totient is φ = 13762560.

The previous prime is 51613433. The next prime is 51613447. The reversal of 51613440 is 4431615.

It is an interprime number because it is at equal distance from previous prime (51613433) and next prime (51613447).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 51613440.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51613447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2881 + ... + 10560.

Almost surely, 2^51613440 is an apocalyptic number.

It is an amenable number.

51613440 is an abundant number, since it is smaller than the sum of its proper divisors (113239248).

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

51613440 is a wasteful number, since it uses less digits than its factorization.

51613440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13465 (or 13451 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 51613440 is about 7184.2494388767. The cubic root of 51613440 is about 372.3239171982.

The spelling of 51613440 in words is "fifty-one million, six hundred thirteen thousand, four hundred forty".