689969993 has 2 divisors, whose sum is σ = 689969994. Its totient is φ = 689969992.

The previous prime is 689969981. The next prime is 689970023. The reversal of 689969993 is 399969986.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 679749184 + 10220809 = 26072^2 + 3197^2 .

It is a cyclic number.

It is not a de Polignac number, because 689969993 - 2¹² = 689965897 is a prime.

It is not a weakly prime, because it can be changed into another prime (689969923) 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, 344984996 + 344984997.

It is an arithmetic number, because the mean of its divisors is an integer number (344984997).

Almost surely, 2^689969993 is an apocalyptic number.

It is an amenable number.

689969993 is a deficient number, since it is larger than the sum of its proper divisors (1).

689969993 is an equidigital number, since it uses as much as digits as its factorization.

689969993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51018336, while the sum is 68.

The square root of 689969993 is about 26267.2798934340. The cubic root of 689969993 is about 883.6427824637.

The spelling of 689969993 in words is "six hundred eighty-nine million, nine hundred sixty-nine thousand, nine hundred ninety-three".