694396721 has 2 divisors, whose sum is σ = 694396722. Its totient is φ = 694396720.

The previous prime is 694396711. The next prime is 694396811. The reversal of 694396721 is 127693496.

It is a happy number.

694396721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 574800625 + 119596096 = 23975^2 + 10936^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-694396721 is a prime.

It is a super-2 number, since 2×694396721² = 964373612271103682, which contains 22 as substring.

It is equal to p_35977664 and since 694396721 and 35977664 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (694396711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 347198360 + 347198361.

It is an arithmetic number, because the mean of its divisors is an integer number (347198361).

Almost surely, 2^694396721 is an apocalyptic number.

It is an amenable number.

694396721 is a deficient number, since it is larger than the sum of its proper divisors (1).

694396721 is an equidigital number, since it uses as much as digits as its factorization.

694396721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 489888, while the sum is 47.

The square root of 694396721 is about 26351.4083304859. The cubic root of 694396721 is about 885.5285216966.

The spelling of 694396721 in words is "six hundred ninety-four million, three hundred ninety-six thousand, seven hundred twenty-one".