51701621 has 2 divisors, whose sum is σ = 51701622. Its totient is φ = 51701620.

The previous prime is 51701581. The next prime is 51701623. The reversal of 51701621 is 12610715.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51122500 + 579121 = 7150^2 + 761^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51701621 is a prime.

It is a super-2 number, since 2×51701621² = 5346115228055282, which contains 22 as substring.

Together with 51701623, 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 (51701623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25850810 + 25850811.

It is an arithmetic number, because the mean of its divisors is an integer number (25850811).

Almost surely, 2^51701621 is an apocalyptic number.

It is an amenable number.

51701621 is a deficient number, since it is larger than the sum of its proper divisors (1).

51701621 is an equidigital number, since it uses as much as digits as its factorization.

51701621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 420, while the sum is 23.

The square root of 51701621 is about 7190.3839257720. The cubic root of 51701621 is about 372.5358336772.

The spelling of 51701621 in words is "fifty-one million, seven hundred one thousand, six hundred twenty-one".