256172071 has 4 divisors (see below), whose sum is σ = 256339000. Its totient is φ = 256005144.

The previous prime is 256171987. The next prime is 256172089. The reversal of 256172071 is 170271652.

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 256172071 - 2⁷ = 256171943 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 (256172471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81141 + ... + 84238.

It is an arithmetic number, because the mean of its divisors is an integer number (64084750).

Almost surely, 2^256172071 is an apocalyptic number.

256172071 is a deficient number, since it is larger than the sum of its proper divisors (166929).

256172071 is a wasteful number, since it uses less digits than its factorization.

256172071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166928.

The product of its (nonzero) digits is 5880, while the sum is 31.

The square root of 256172071 is about 16005.3763154760. The cubic root of 256172071 is about 635.1026523033.

The spelling of 256172071 in words is "two hundred fifty-six million, one hundred seventy-two thousand, seventy-one".