256420155 has 8 divisors (see below), whose sum is σ = 410272272. Its totient is φ = 136757408.

The previous prime is 256420139. The next prime is 256420159. The reversal of 256420155 is 551024652.

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 256420155 - 2⁴ = 256420139 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256420159) 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, 8547324 + ... + 8547353.

It is an arithmetic number, because the mean of its divisors is an integer number (51284034).

Almost surely, 2^256420155 is an apocalyptic number.

256420155 is a deficient number, since it is larger than the sum of its proper divisors (153852117).

256420155 is a wasteful number, since it uses less digits than its factorization.

256420155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17094685.

The product of its (nonzero) digits is 12000, while the sum is 30.

The square root of 256420155 is about 16013.1244608914. The cubic root of 256420155 is about 635.3076030508.

The spelling of 256420155 in words is "two hundred fifty-six million, four hundred twenty thousand, one hundred fifty-five".