51197640 has 128 divisors (see below), whose sum is σ = 170069760. Its totient is φ = 12248064.

The previous prime is 51197639. The next prime is 51197683. The reversal of 51197640 is 4679115.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 57277 + ... + 58163.

It is an arithmetic number, because the mean of its divisors is an integer number (1328670).

Almost surely, 2^51197640 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 51197640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85034880).

51197640 is an abundant number, since it is smaller than the sum of its proper divisors (118872120).

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

51197640 is a wasteful number, since it uses less digits than its factorization.

51197640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 951 (or 947 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 33.

The square root of 51197640 is about 7155.2526160856. The cubic root of 51197640 is about 371.3214013151.

The spelling of 51197640 in words is "fifty-one million, one hundred ninety-seven thousand, six hundred forty".