689989901 has 2 divisors, whose sum is σ = 689989902. Its totient is φ = 689989900.

The previous prime is 689989843. The next prime is 689989907. The reversal of 689989901 is 109989986.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 566202025 + 123787876 = 23795^2 + 11126^2 .

It is a cyclic number.

It is not a de Polignac number, because 689989901 - 2¹⁴ = 689973517 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (689989907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344994950 + 344994951.

It is an arithmetic number, because the mean of its divisors is an integer number (344994951).

Almost surely, 2^689989901 is an apocalyptic number.

It is an amenable number.

689989901 is a deficient number, since it is larger than the sum of its proper divisors (1).

689989901 is an equidigital number, since it uses as much as digits as its factorization.

689989901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2519424, while the sum is 59.

The square root of 689989901 is about 26267.6588412443. The cubic root of 689989901 is about 883.6512810899.

The spelling of 689989901 in words is "six hundred eighty-nine million, nine hundred eighty-nine thousand, nine hundred one".