256171213 has 4 divisors (see below), whose sum is σ = 256214848. Its totient is φ = 256127580.

The previous prime is 256171199. The next prime is 256171219. The reversal of 256171213 is 312171652.

It is a happy number.

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 256171213 - 2²⁵ = 222616781 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256171219) 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, 11331 + ... + 25312.

It is an arithmetic number, because the mean of its divisors is an integer number (64053712).

Almost surely, 2^256171213 is an apocalyptic number.

It is an amenable number.

256171213 is a deficient number, since it is larger than the sum of its proper divisors (43635).

256171213 is an equidigital number, since it uses as much as digits as its factorization.

256171213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43634.

The product of its digits is 2520, while the sum is 28.

The square root of 256171213 is about 16005.3495119601. The cubic root of 256171213 is about 635.1019432504.

The spelling of 256171213 in words is "two hundred fifty-six million, one hundred seventy-one thousand, two hundred thirteen".