51293840 has 160 divisors (see below), whose sum is σ = 139324416. Its totient is φ = 17418240.

The previous prime is 51293839. The next prime is 51293849. The reversal of 51293840 is 4839215.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 51293797 and 51293806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51293849) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1192859 + ... + 1192901.

Almost surely, 2^51293840 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 51293840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69662208).

51293840 is an abundant number, since it is smaller than the sum of its proper divisors (88030576).

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

51293840 is a wasteful number, since it uses less digits than its factorization.

51293840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 51293840 is about 7161.9717955323. The cubic root of 51293840 is about 371.5538258884.

The spelling of 51293840 in words is "fifty-one million, two hundred ninety-three thousand, eight hundred forty".