51356621 has 2 divisors, whose sum is σ = 51356622. Its totient is φ = 51356620.

The previous prime is 51356611. The next prime is 51356623. The reversal of 51356621 is 12665315.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47803396 + 3553225 = 6914^2 + 1885^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51356621 is a prime.

Together with 51356623, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51356623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25678310 + 25678311.

It is an arithmetic number, because the mean of its divisors is an integer number (25678311).

Almost surely, 2^51356621 is an apocalyptic number.

It is an amenable number.

51356621 is a deficient number, since it is larger than the sum of its proper divisors (1).

51356621 is an equidigital number, since it uses as much as digits as its factorization.

51356621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5400, while the sum is 29.

The square root of 51356621 is about 7166.3533962539. The cubic root of 51356621 is about 371.7053516232.

The spelling of 51356621 in words is "fifty-one million, three hundred fifty-six thousand, six hundred twenty-one".