697370021 has 2 divisors, whose sum is σ = 697370022. Its totient is φ = 697370020.

The previous prime is 697369963. The next prime is 697370027. The reversal of 697370021 is 120073796.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 639381796 + 57988225 = 25286^2 + 7615^2 .

It is a cyclic number.

It is not a de Polignac number, because 697370021 - 2¹⁸ = 697107877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (697370027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 348685010 + 348685011.

It is an arithmetic number, because the mean of its divisors is an integer number (348685011).

Almost surely, 2^697370021 is an apocalyptic number.

It is an amenable number.

697370021 is a deficient number, since it is larger than the sum of its proper divisors (1).

697370021 is an equidigital number, since it uses as much as digits as its factorization.

697370021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15876, while the sum is 35.

The square root of 697370021 is about 26407.7644074617. The cubic root of 697370021 is about 886.7906210303.

The spelling of 697370021 in words is "six hundred ninety-seven million, three hundred seventy thousand, twenty-one".