694291021 has 2 divisors, whose sum is σ = 694291022. Its totient is φ = 694291020.

The previous prime is 694290991. The next prime is 694291057. The reversal of 694291021 is 120192496.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 693268900 + 1022121 = 26330^2 + 1011^2 .

It is a cyclic number.

It is not a de Polignac number, because 694291021 - 2⁷ = 694290893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (694291061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 347145510 + 347145511.

It is an arithmetic number, because the mean of its divisors is an integer number (347145511).

Almost surely, 2^694291021 is an apocalyptic number.

It is an amenable number.

694291021 is a deficient number, since it is larger than the sum of its proper divisors (1).

694291021 is an equidigital number, since it uses as much as digits as its factorization.

694291021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 694291021 is about 26349.4026687513. The cubic root of 694291021 is about 885.4835881538.

The spelling of 694291021 in words is "six hundred ninety-four million, two hundred ninety-one thousand, twenty-one".