51256120253 has 4 divisors (see below), whose sum is σ = 55198898748. Its totient is φ = 47313341760.

The previous prime is 51256120247. The next prime is 51256120261. The reversal of 51256120253 is 35202165215.

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 19500167449 + 31755952804 = 139643^2 + 178202^2 .

It is a cyclic number.

It is not a de Polignac number, because 51256120253 - 2⁶ = 51256120189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51256120753) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1971389228 + ... + 1971389253.

It is an arithmetic number, because the mean of its divisors is an integer number (13799724687).

Almost surely, 2^51256120253 is an apocalyptic number.

It is an amenable number.

51256120253 is a deficient number, since it is larger than the sum of its proper divisors (3942778495).

51256120253 is a wasteful number, since it uses less digits than its factorization.

51256120253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3942778494.

The product of its (nonzero) digits is 18000, while the sum is 32.

Adding to 51256120253 its reverse (35202165215), we get a palindrome (86458285468).

The spelling of 51256120253 in words is "fifty-one billion, two hundred fifty-six million, one hundred twenty thousand, two hundred fifty-three".