256315909 has 16 divisors (see below), whose sum is σ = 279072000. Its totient is φ = 234581184.

The previous prime is 256315907. The next prime is 256315931. The reversal of 256315909 is 909513652.

It is a happy number.

It is not a de Polignac number, because 256315909 - 2¹ = 256315907 is a prime.

It is a super-3 number, since 3×256315909³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256315901) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 103524 + ... + 105970.

It is an arithmetic number, because the mean of its divisors is an integer number (17442000).

Almost surely, 2^256315909 is an apocalyptic number.

It is an amenable number.

256315909 is a deficient number, since it is larger than the sum of its proper divisors (22756091).

256315909 is a wasteful number, since it uses less digits than its factorization.

256315909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2652.

The product of its (nonzero) digits is 72900, while the sum is 40.

The square root of 256315909 is about 16009.8691125193. The cubic root of 256315909 is about 635.2214979455.

The spelling of 256315909 in words is "two hundred fifty-six million, three hundred fifteen thousand, nine hundred nine".