256661461 has 12 divisors (see below), whose sum is σ = 316129068. Its totient is φ = 207053952.

The previous prime is 256661429. The next prime is 256661467. The reversal of 256661461 is 164166652.

It can be written as a sum of positive squares in 2 ways, for example, as 68807025 + 187854436 = 8295^2 + 13706^2 .

It is not a de Polignac number, because 256661461 - 2⁵ = 256661429 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 256661461.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256661467) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 153226 + ... + 154891.

It is an arithmetic number, because the mean of its divisors is an integer number (26344089).

Almost surely, 2^256661461 is an apocalyptic number.

It is an amenable number.

256661461 is a deficient number, since it is larger than the sum of its proper divisors (59467607).

256661461 is a wasteful number, since it uses less digits than its factorization.

256661461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308148 (or 308141 counting only the distinct ones).

The product of its digits is 51840, while the sum is 37.

The square root of 256661461 is about 16020.6573210964. The cubic root of 256661461 is about 635.5068274740.

The spelling of 256661461 in words is "two hundred fifty-six million, six hundred sixty-one thousand, four hundred sixty-one".