635969 has 2 divisors, whose sum is σ = 635970. Its totient is φ = 635968.

The previous prime is 635959. The next prime is 635977. The reversal of 635969 is 969536.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 600625 + 35344 = 775^2 + 188^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-635969 is a prime.

It is a super-2 number, since 2×635969² = 808913137922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (635909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 317984 + 317985.

It is an arithmetic number, because the mean of its divisors is an integer number (317985).

2⁶³⁵⁹⁶⁹ is an apocalyptic number.

It is an amenable number.

635969 is a deficient number, since it is larger than the sum of its proper divisors (1).

635969 is an equidigital number, since it uses as much as digits as its factorization.

635969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43740, while the sum is 38.

The square root of 635969 is about 797.4766454261. The cubic root of 635969 is about 85.9960787828.

The spelling of 635969 in words is "six hundred thirty-five thousand, nine hundred sixty-nine".