256171547 has 4 divisors (see below), whose sum is σ = 269654280. Its totient is φ = 242688816.

The previous prime is 256171523. The next prime is 256171549. The reversal of 256171547 is 745171652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 256171547 - 2¹² = 256167451 is a prime.

It is a super-2 number, since 2×256171547² = 131247722984746418, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 256171547.

It is not an unprimeable number, because it can be changed into a prime (256171549) 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, 6741338 + ... + 6741375.

It is an arithmetic number, because the mean of its divisors is an integer number (67413570).

Almost surely, 2^256171547 is an apocalyptic number.

256171547 is a deficient number, since it is larger than the sum of its proper divisors (13482733).

256171547 is a wasteful number, since it uses less digits than its factorization.

256171547 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13482732.

The product of its digits is 58800, while the sum is 38.

The square root of 256171547 is about 16005.3599459681. The cubic root of 256171547 is about 635.1022192688.

The spelling of 256171547 in words is "two hundred fifty-six million, one hundred seventy-one thousand, five hundred forty-seven".