256505149 has 4 divisors (see below), whose sum is σ = 270005440. Its totient is φ = 243004860.

The previous prime is 256505101. The next prime is 256505159. The reversal of 256505149 is 941505652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 256505149 - 2¹¹ = 256503101 is a prime.

It is a Duffinian number.

256505149 is a modest number, since divided by 5149 gives 2565 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256505159) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6750117 + ... + 6750154.

It is an arithmetic number, because the mean of its divisors is an integer number (67501360).

Almost surely, 2^256505149 is an apocalyptic number.

It is an amenable number.

256505149 is a deficient number, since it is larger than the sum of its proper divisors (13500291).

256505149 is a wasteful number, since it uses less digits than its factorization.

256505149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13500290.

The product of its (nonzero) digits is 54000, while the sum is 37.

The square root of 256505149 is about 16015.7781265850. The cubic root of 256505149 is about 635.3777891216.

The spelling of 256505149 in words is "two hundred fifty-six million, five hundred five thousand, one hundred forty-nine".