51637021 has 2 divisors, whose sum is σ = 51637022. Its totient is φ = 51637020.

The previous prime is 51637013. The next prime is 51637063. The reversal of 51637021 is 12073615.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29311396 + 22325625 = 5414^2 + 4725^2 .

It is a cyclic number.

It is not a de Polignac number, because 51637021 - 2³ = 51637013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51637121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25818510 + 25818511.

It is an arithmetic number, because the mean of its divisors is an integer number (25818511).

Almost surely, 2^51637021 is an apocalyptic number.

It is an amenable number.

51637021 is a deficient number, since it is larger than the sum of its proper divisors (1).

51637021 is an equidigital number, since it uses as much as digits as its factorization.

51637021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 51637021 is about 7185.8904110764. The cubic root of 51637021 is about 372.3806106585.

The spelling of 51637021 in words is "fifty-one million, six hundred thirty-seven thousand, twenty-one".