689541257 has 2 divisors, whose sum is σ = 689541258. Its totient is φ = 689541256.

The previous prime is 689541221. The next prime is 689541271. The reversal of 689541257 is 752145986.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 564347536 + 125193721 = 23756^2 + 11189^2 .

It is a cyclic number.

It is not a de Polignac number, because 689541257 - 2⁸ = 689541001 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (689541557) 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, 344770628 + 344770629.

It is an arithmetic number, because the mean of its divisors is an integer number (344770629).

Almost surely, 2^689541257 is an apocalyptic number.

It is an amenable number.

689541257 is a deficient number, since it is larger than the sum of its proper divisors (1).

689541257 is an equidigital number, since it uses as much as digits as its factorization.

689541257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 604800, while the sum is 47.

The square root of 689541257 is about 26259.1175975127. The cubic root of 689541257 is about 883.4597175124.

The spelling of 689541257 in words is "six hundred eighty-nine million, five hundred forty-one thousand, two hundred fifty-seven".