256545261 has 12 divisors (see below), whose sum is σ = 423503392. Its totient is φ = 146597256.

The previous prime is 256545257. The next prime is 256545271. The reversal of 256545261 is 162545652.

256545261 is a `hidden beast` number, since 2 + 56 + 545 + 2 + 61 = 666.

It is not a de Polignac number, because 256545261 - 2² = 256545257 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256545251) 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, 2036011 + ... + 2036136.

Almost surely, 2^256545261 is an apocalyptic number.

256545261 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

256545261 is a deficient number, since it is larger than the sum of its proper divisors (166958131).

256545261 is a wasteful number, since it uses less digits than its factorization.

256545261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4072160 (or 4072157 counting only the distinct ones).

The product of its digits is 72000, while the sum is 36.

The square root of 256545261 is about 16017.0303427321. The cubic root of 256545261 is about 635.4109072943.

The spelling of 256545261 in words is "two hundred fifty-six million, five hundred forty-five thousand, two hundred sixty-one".