51397285 has 4 divisors (see below), whose sum is σ = 61676748. Its totient is φ = 41117824.

The previous prime is 51397277. The next prime is 51397289. The reversal of 51397285 is 58279315.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20738916 + 30658369 = 4554^2 + 5537^2 .

It is a cyclic number.

It is not a de Polignac number, because 51397285 - 2³ = 51397277 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51397289) 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, 5139724 + ... + 5139733.

It is an arithmetic number, because the mean of its divisors is an integer number (15419187).

Almost surely, 2^51397285 is an apocalyptic number.

It is an amenable number.

51397285 is a deficient number, since it is larger than the sum of its proper divisors (10279463).

51397285 is a wasteful number, since it uses less digits than its factorization.

51397285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10279462.

The product of its digits is 75600, while the sum is 40.

The square root of 51397285 is about 7169.1899821388. The cubic root of 51397285 is about 371.8034307578.

The spelling of 51397285 in words is "fifty-one million, three hundred ninety-seven thousand, two hundred eighty-five".