256673969 has 2 divisors, whose sum is σ = 256673970. Its totient is φ = 256673968.

The previous prime is 256673959. The next prime is 256673971. The reversal of 256673969 is 969376652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 231040000 + 25633969 = 15200^2 + 5063^2 .

It is a cyclic number.

It is not a de Polignac number, because 256673969 - 2¹² = 256669873 is a prime.

It is a super-2 number, since 2×256673969² = 131763052724425922, which contains 22 as substring.

Together with 256673971, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256673969.

It is not a weakly prime, because it can be changed into another prime (256673929) 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, 128336984 + 128336985.

It is an arithmetic number, because the mean of its divisors is an integer number (128336985).

Almost surely, 2^256673969 is an apocalyptic number.

It is an amenable number.

256673969 is a deficient number, since it is larger than the sum of its proper divisors (1).

256673969 is an equidigital number, since it uses as much as digits as its factorization.

256673969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3674160, while the sum is 53.

The square root of 256673969 is about 16021.0476873393. The cubic root of 256673969 is about 635.5171507877.

The spelling of 256673969 in words is "two hundred fifty-six million, six hundred seventy-three thousand, nine hundred sixty-nine".