694238921 has 2 divisors, whose sum is σ = 694238922. Its totient is φ = 694238920.

The previous prime is 694238879. The next prime is 694238933. The reversal of 694238921 is 129832496.

694238921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 624750025 + 69488896 = 24995^2 + 8336^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-694238921 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (694238971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 347119460 + 347119461.

It is an arithmetic number, because the mean of its divisors is an integer number (347119461).

Almost surely, 2^694238921 is an apocalyptic number.

It is an amenable number.

694238921 is a deficient number, since it is larger than the sum of its proper divisors (1).

694238921 is an equidigital number, since it uses as much as digits as its factorization.

694238921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 186624, while the sum is 44.

The square root of 694238921 is about 26348.4140129914. The cubic root of 694238921 is about 885.4614385328.

The spelling of 694238921 in words is "six hundred ninety-four million, two hundred thirty-eight thousand, nine hundred twenty-one".