51397760 has 32 divisors (see below), whose sum is σ = 122874300. Its totient is φ = 20558848.

The previous prime is 51397739. The next prime is 51397763. The reversal of 51397760 is 6779315.

It can be written as a sum of positive squares in 2 ways, for example, as 50580544 + 817216 = 7112^2 + 904^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is not an unprimeable number, because it can be changed into a prime (51397763) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39515 + ... + 40794.

Almost surely, 2^51397760 is an apocalyptic number.

It is an amenable number.

51397760 is an abundant number, since it is smaller than the sum of its proper divisors (71476540).

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

51397760 is an equidigital number, since it uses as much as digits as its factorization.

51397760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80328 (or 80316 counting only the distinct ones).

The product of its (nonzero) digits is 39690, while the sum is 38.

The square root of 51397760 is about 7169.2231099332. The cubic root of 51397760 is about 371.8045761236.

The spelling of 51397760 in words is "fifty-one million, three hundred ninety-seven thousand, seven hundred sixty".