694861021 has 2 divisors, whose sum is σ = 694861022. Its totient is φ = 694861020.

The previous prime is 694861007. The next prime is 694861051. The reversal of 694861021 is 120168496.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 531302500 + 163558521 = 23050^2 + 12789^2 .

It is a cyclic number.

It is not a de Polignac number, because 694861021 - 2²⁹ = 157990109 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (694861051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 347430510 + 347430511.

It is an arithmetic number, because the mean of its divisors is an integer number (347430511).

Almost surely, 2^694861021 is an apocalyptic number.

It is an amenable number.

694861021 is a deficient number, since it is larger than the sum of its proper divisors (1).

694861021 is an equidigital number, since it uses as much as digits as its factorization.

694861021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 694861021 is about 26360.2166341629. The cubic root of 694861021 is about 885.7258437159.

It can be divided in two parts, 69486 and 1021, that added together give a palindrome (70507).

The spelling of 694861021 in words is "six hundred ninety-four million, eight hundred sixty-one thousand, twenty-one".