51238440 has 256 divisors, whose sum is σ = 196992000. Its totient is φ = 11715840.

The previous prime is 51238417. The next prime is 51238463. The reversal of 51238440 is 4483215.

It is an interprime number because it is at equal distance from previous prime (51238417) and next prime (51238463).

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

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, 225607 + ... + 225833.

It is an arithmetic number, because the mean of its divisors is an integer number (769500).

Almost surely, 2^51238440 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 51238440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98496000).

51238440 is an abundant number, since it is smaller than the sum of its proper divisors (145753560).

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

51238440 is a wasteful number, since it uses less digits than its factorization.

51238440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277 (or 267 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 51238440 is about 7158.1031006825. The cubic root of 51238440 is about 371.4200119188.

The spelling of 51238440 in words is "fifty-one million, two hundred thirty-eight thousand, four hundred forty".