256352121 has 21 divisors (see below), whose sum is σ = 385001599. Its totient is φ = 170613216.

The previous prime is 256352119. The next prime is 256352137. The reversal of 256352121 is 121253652.

It is a happy number.

The square root of 256352121 is 16011.

It is a perfect power (a square), and thus also a powerful number.

256352121 is a `hidden beast` number, since 2 + 5 + 635 + 2 + 1 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 157628025 + 98724096 = 12555^2 + 9936^2 .

It is not a de Polignac number, because 256352121 - 2¹ = 256352119 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256352191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 432001 + ... + 432593.

Almost surely, 2^256352121 is an apocalyptic number.

256352121 is the 16011-st square number.

256352121 is the 8006-th centered octagonal number.

It is an amenable number.

256352121 is a deficient number, since it is larger than the sum of its proper divisors (128649478).

256352121 is an frugal number, since it uses more digits than its factorization.

256352121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1204 (or 596 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The cubic root of 256352121 is about 635.2514109772.

Multiplying 256352121 by its product of digits (3600), we get a square (922867635600 = 960660²).

The spelling of 256352121 in words is "two hundred fifty-six million, three hundred fifty-two thousand, one hundred twenty-one".