256505151 has 24 divisors (see below), whose sum is σ = 401968560. Its totient is φ = 145055232.

The previous prime is 256505101. The next prime is 256505159. The reversal of 256505151 is 151505652.

It is not a de Polignac number, because 256505151 - 2¹¹ = 256503103 is a prime.

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 pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5265 + ... + 23253.

It is an arithmetic number, because the mean of its divisors is an integer number (16748690).

Almost surely, 2^256505151 is an apocalyptic number.

256505151 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

256505151 is a deficient number, since it is larger than the sum of its proper divisors (145463409).

256505151 is a wasteful number, since it uses less digits than its factorization.

256505151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18103 (or 18096 counting only the distinct ones).

The product of its (nonzero) digits is 7500, while the sum is 30.

The square root of 256505151 is about 16015.7781890235. The cubic root of 256505151 is about 635.3777907730.

The spelling of 256505151 in words is "two hundred fifty-six million, five hundred five thousand, one hundred fifty-one".