51397820 has 12 divisors (see below), whose sum is σ = 107935464. Its totient is φ = 20559120.

The previous prime is 51397813. The next prime is 51397867. The reversal of 51397820 is 2879315.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1284926 + ... + 1284965.

It is an arithmetic number, because the mean of its divisors is an integer number (8994622).

Almost surely, 2^51397820 is an apocalyptic number.

It is an amenable number.

51397820 is an abundant number, since it is smaller than the sum of its proper divisors (56537644).

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

51397820 is a wasteful number, since it uses less digits than its factorization.

51397820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2569900 (or 2569898 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 51397820 is about 7169.2272944858. The cubic root of 51397820 is about 371.8047208009.

The spelling of 51397820 in words is "fifty-one million, three hundred ninety-seven thousand, eight hundred twenty".