689312557 has 2 divisors, whose sum is σ = 689312558. Its totient is φ = 689312556.

The previous prime is 689312527. The next prime is 689312563. The reversal of 689312557 is 755213986.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 525830761 + 163481796 = 22931^2 + 12786^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-689312557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (689312527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344656278 + 344656279.

It is an arithmetic number, because the mean of its divisors is an integer number (344656279).

Almost surely, 2^689312557 is an apocalyptic number.

It is an amenable number.

689312557 is a deficient number, since it is larger than the sum of its proper divisors (1).

689312557 is an equidigital number, since it uses as much as digits as its factorization.

689312557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 453600, while the sum is 46.

The square root of 689312557 is about 26254.7625584388. The cubic root of 689312557 is about 883.3620344141.

The spelling of 689312557 in words is "six hundred eighty-nine million, three hundred twelve thousand, five hundred fifty-seven".