51021697 has 2 divisors, whose sum is σ = 51021698. Its totient is φ = 51021696.

The previous prime is 51021683. The next prime is 51021713. The reversal of 51021697 is 79612015.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43046721 + 7974976 = 6561^2 + 2824^2 .

It is a cyclic number.

It is not a de Polignac number, because 51021697 - 2⁷ = 51021569 is a prime.

It is not a weakly prime, because it can be changed into another prime (51021637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25510848 + 25510849.

It is an arithmetic number, because the mean of its divisors is an integer number (25510849).

Almost surely, 2^51021697 is an apocalyptic number.

It is an amenable number.

51021697 is a deficient number, since it is larger than the sum of its proper divisors (1).

51021697 is an equidigital number, since it uses as much as digits as its factorization.

51021697 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3780, while the sum is 31.

The square root of 51021697 is about 7142.9473608588. The cubic root of 51021697 is about 370.8955588829.

The spelling of 51021697 in words is "fifty-one million, twenty-one thousand, six hundred ninety-seven".