51247840 has 48 divisors (see below), whose sum is σ = 138372192. Its totient is φ = 17570304.

The previous prime is 51247837. The next prime is 51247919. The reversal of 51247840 is 4874215.

It is a super-2 number, since 2×51247840² = 5252682209331200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21759 + ... + 23998.

It is an arithmetic number, because the mean of its divisors is an integer number (2882754).

Almost surely, 2^51247840 is an apocalyptic number.

It is an amenable number.

51247840 is an abundant number, since it is smaller than the sum of its proper divisors (87124352).

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

51247840 is a wasteful number, since it uses less digits than its factorization.

51247840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45779 (or 45771 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 51247840 is about 7158.7596691047. The cubic root of 51247840 is about 371.4427236084.

The spelling of 51247840 in words is "fifty-one million, two hundred forty-seven thousand, eight hundred forty".