256505995 has 8 divisors (see below), whose sum is σ = 307916784. Its totient is φ = 205131744.

The previous prime is 256505993. The next prime is 256505999. The reversal of 256505995 is 599505652.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 256505995 - 2¹ = 256505993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256505993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9937 + ... + 24733.

It is an arithmetic number, because the mean of its divisors is an integer number (38489598).

Almost surely, 2^256505995 is an apocalyptic number.

256505995 is a deficient number, since it is larger than the sum of its proper divisors (51410789).

256505995 is a wasteful number, since it uses less digits than its factorization.

256505995 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18269.

The product of its (nonzero) digits is 607500, while the sum is 46.

The square root of 256505995 is about 16015.8045380181. The cubic root of 256505995 is about 635.3784876508.

The spelling of 256505995 in words is "two hundred fifty-six million, five hundred five thousand, nine hundred ninety-five".