256172399 has 8 divisors (see below), whose sum is σ = 302864160. Its totient is φ = 212004576.

The previous prime is 256172393. The next prime is 256172467. The reversal of 256172399 is 993271652.

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

It is not a de Polignac number, because 256172399 - 2¹² = 256168303 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 (256172393) 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, 630764 + ... + 631169.

It is an arithmetic number, because the mean of its divisors is an integer number (37858020).

Almost surely, 2^256172399 is an apocalyptic number.

256172399 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

256172399 is a deficient number, since it is larger than the sum of its proper divisors (46691761).

256172399 is a wasteful number, since it uses less digits than its factorization.

256172399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1261969.

The product of its digits is 204120, while the sum is 44.

The square root of 256172399 is about 16005.3865620297. The cubic root of 256172399 is about 635.1029233627.

The spelling of 256172399 in words is "two hundred fifty-six million, one hundred seventy-two thousand, three hundred ninety-nine".