51885413621 has 4 divisors (see below), whose sum is σ = 52361426700. Its totient is φ = 51409400544.

The previous prime is 51885413563. The next prime is 51885413677. The reversal of 51885413621 is 12631458815.

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 34017744721 + 17867668900 = 184439^2 + 133670^2 .

It is a cyclic number.

It is not a de Polignac number, because 51885413621 - 2⁶ = 51885413557 is a prime.

It is a super-2 number, since 2×51885413621² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51885413681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 238006376 + ... + 238006593.

It is an arithmetic number, because the mean of its divisors is an integer number (13090356675).

Almost surely, 2^51885413621 is an apocalyptic number.

It is an amenable number.

51885413621 is a deficient number, since it is larger than the sum of its proper divisors (476013079).

51885413621 is a wasteful number, since it uses less digits than its factorization.

51885413621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476013078.

The product of its digits is 230400, while the sum is 44.

The spelling of 51885413621 in words is "fifty-one billion, eight hundred eighty-five million, four hundred thirteen thousand, six hundred twenty-one".