689667157 has 2 divisors, whose sum is σ = 689667158. Its totient is φ = 689667156.

The previous prime is 689667151. The next prime is 689667197. The reversal of 689667157 is 751766986.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 492573636 + 197093521 = 22194^2 + 14039^2 .

It is a cyclic number.

It is not a de Polignac number, because 689667157 - 2¹⁹ = 689142869 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 689667098 and 689667107.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (689667151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344833578 + 344833579.

It is an arithmetic number, because the mean of its divisors is an integer number (344833579).

Almost surely, 2^689667157 is an apocalyptic number.

It is an amenable number.

689667157 is a deficient number, since it is larger than the sum of its proper divisors (1).

689667157 is an equidigital number, since it uses as much as digits as its factorization.

689667157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3810240, while the sum is 55.

The square root of 689667157 is about 26261.5147506765. The cubic root of 689667157 is about 883.5134831180.

The spelling of 689667157 in words is "six hundred eighty-nine million, six hundred sixty-seven thousand, one hundred fifty-seven".