51157621 has 2 divisors, whose sum is σ = 51157622. Its totient is φ = 51157620.

The previous prime is 51157619. The next prime is 51157669. The reversal of 51157621 is 12675115.

51157621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32547025 + 18610596 = 5705^2 + 4314^2 .

It is a cyclic number.

It is not a de Polignac number, because 51157621 - 2¹ = 51157619 is a prime.

Together with 51157619, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 51157621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51197621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25578810 + 25578811.

It is an arithmetic number, because the mean of its divisors is an integer number (25578811).

Almost surely, 2^51157621 is an apocalyptic number.

It is an amenable number.

51157621 is a deficient number, since it is larger than the sum of its proper divisors (1).

51157621 is an equidigital number, since it uses as much as digits as its factorization.

51157621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2100, while the sum is 28.

The square root of 51157621 is about 7152.4555923123. The cubic root of 51157621 is about 371.2246274233.

The spelling of 51157621 in words is "fifty-one million, one hundred fifty-seven thousand, six hundred twenty-one".