256666669 has 16 divisors (see below), whose sum is σ = 302076288. Its totient is φ = 213475392.

The previous prime is 256666643. The next prime is 256666703. The reversal of 256666669 is 966666652.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 256666669 - 2¹¹ = 256664621 is a prime.

It is a super-2 number, since 2×256666669² = 131755557951111122, which contains 22 as substring.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256666369) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113619 + ... + 115855.

It is an arithmetic number, because the mean of its divisors is an integer number (18879768).

Almost surely, 2^256666669 is an apocalyptic number.

It is an amenable number.

256666669 is a deficient number, since it is larger than the sum of its proper divisors (45409619).

256666669 is a wasteful number, since it uses less digits than its factorization.

256666669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2724.

The product of its digits is 4199040, while the sum is 52.

The square root of 256666669 is about 16020.8198604191. The cubic root of 256666669 is about 635.5111258692.

The spelling of 256666669 in words is "two hundred fifty-six million, six hundred sixty-six thousand, six hundred sixty-nine".