256064661 has 12 divisors (see below), whose sum is σ = 376140960. Its totient is φ = 167816040.

The previous prime is 256064657. The next prime is 256064671. The reversal of 256064661 is 166460652.

It is a happy number.

256064661 is a `hidden beast` number, since 2 + 5 + 6 + 0 + 646 + 6 + 1 = 666.

It is not a de Polignac number, because 256064661 - 2² = 256064657 is a prime.

It is a super-2 number, since 2×256064661² = 131138221226089842, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256064671) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 240585 + ... + 241646.

It is an arithmetic number, because the mean of its divisors is an integer number (31345080).

Almost surely, 2^256064661 is an apocalyptic number.

It is an amenable number.

256064661 is a deficient number, since it is larger than the sum of its proper divisors (120076299).

256064661 is a wasteful number, since it uses less digits than its factorization.

256064661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 482296 (or 482293 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 256064661 is about 16002.0205286707. The cubic root of 256064661 is about 635.0138761512.

The spelling of 256064661 in words is "two hundred fifty-six million, sixty-four thousand, six hundred sixty-one".