690844643 has 2 divisors, whose sum is σ = 690844644. Its totient is φ = 690844642.

The previous prime is 690844639. The next prime is 690844669. The reversal of 690844643 is 346448096.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 690844643 - 2² = 690844639 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 690844594 and 690844603.

It is not a weakly prime, because it can be changed into another prime (690844603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345422321 + 345422322.

It is an arithmetic number, because the mean of its divisors is an integer number (345422322).

Almost surely, 2^690844643 is an apocalyptic number.

690844643 is a deficient number, since it is larger than the sum of its proper divisors (1).

690844643 is an equidigital number, since it uses as much as digits as its factorization.

690844643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 497664, while the sum is 44.

The square root of 690844643 is about 26283.9236606714. The cubic root of 690844643 is about 884.0160121278.

The spelling of 690844643 in words is "six hundred ninety million, eight hundred forty-four thousand, six hundred forty-three".