256320121 has 8 divisors (see below), whose sum is σ = 264793088. Its totient is φ = 247860000.

The previous prime is 256320107. The next prime is 256320139. The reversal of 256320121 is 121023652.

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 256320121 - 2¹³ = 256311929 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 256320092 and 256320101.

It is not an unprimeable number, because it can be changed into a prime (256320191) 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, 53536 + ... + 58126.

It is an arithmetic number, because the mean of its divisors is an integer number (33099136).

Almost surely, 2^256320121 is an apocalyptic number.

It is an amenable number.

256320121 is a deficient number, since it is larger than the sum of its proper divisors (8472967).

256320121 is a wasteful number, since it uses less digits than its factorization.

256320121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6423.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 256320121 is about 16010.0006558401. Note that the first 3 decimals coincide. The cubic root of 256320121 is about 635.2249774256.

Adding to 256320121 its reverse (121023652), we get a palindrome (377343773).

The spelling of 256320121 in words is "two hundred fifty-six million, three hundred twenty thousand, one hundred twenty-one".