256000121 has 8 divisors (see below), whose sum is σ = 277094664. Its totient is φ = 235105920.

The previous prime is 256000109. The next prime is 256000133. The reversal of 256000121 is 121000652.

It is an interprime number because it is at equal distance from previous prime (256000109) and next prime (256000133).

It can be written as a sum of positive squares in 4 ways, for example, as 37994896 + 218005225 = 6164^2 + 14765^2 .

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 256000121 - 2⁶ = 256000057 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 256000121.

It is not an unprimeable number, because it can be changed into a prime (256000141) 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, 47420 + ... + 52541.

It is an arithmetic number, because the mean of its divisors is an integer number (34636833).

Almost surely, 2^256000121 is an apocalyptic number.

It is an amenable number.

256000121 is a deficient number, since it is larger than the sum of its proper divisors (21094543).

256000121 is a wasteful number, since it uses less digits than its factorization.

256000121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100171.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 256000121 is about 16000.0037812496. The cubic root of 256000121 is about 634.9605208266.

Adding to 256000121 its reverse (121000652), we get a palindrome (377000773).

The spelling of 256000121 in words is "two hundred fifty-six million, one hundred twenty-one", and thus it is an aban number.