51719021 has 2 divisors, whose sum is σ = 51719022. Its totient is φ = 51719020.

The previous prime is 51719011. The next prime is 51719023. The reversal of 51719021 is 12091715.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38316100 + 13402921 = 6190^2 + 3661^2 .

It is a cyclic number.

It is not a de Polignac number, because 51719021 - 2⁶ = 51718957 is a prime.

It is a Sophie Germain prime.

Together with 51719023, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51719023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25859510 + 25859511.

It is an arithmetic number, because the mean of its divisors is an integer number (25859511).

Almost surely, 2^51719021 is an apocalyptic number.

It is an amenable number.

51719021 is a deficient number, since it is larger than the sum of its proper divisors (1).

51719021 is an equidigital number, since it uses as much as digits as its factorization.

51719021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 630, while the sum is 26.

The square root of 51719021 is about 7191.5937732884. The cubic root of 51719021 is about 372.5776208678.

The spelling of 51719021 in words is "fifty-one million, seven hundred nineteen thousand, twenty-one".