689079557 has 2 divisors, whose sum is σ = 689079558. Its totient is φ = 689079556.

The previous prime is 689079551. The next prime is 689079569. The reversal of 689079557 is 755970986.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 376709281 + 312370276 = 19409^2 + 17674^2 .

It is a cyclic number.

It is not a de Polignac number, because 689079557 - 2⁶ = 689079493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (689079551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344539778 + 344539779.

It is an arithmetic number, because the mean of its divisors is an integer number (344539779).

Almost surely, 2^689079557 is an apocalyptic number.

It is an amenable number.

689079557 is a deficient number, since it is larger than the sum of its proper divisors (1).

689079557 is an equidigital number, since it uses as much as digits as its factorization.

689079557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4762800, while the sum is 56.

The square root of 689079557 is about 26250.3248932275. The cubic root of 689079557 is about 883.2624924638.

The spelling of 689079557 in words is "six hundred eighty-nine million, seventy-nine thousand, five hundred fifty-seven".