256711121 has 2 divisors, whose sum is σ = 256711122. Its totient is φ = 256711120.

The previous prime is 256711111. The next prime is 256711151. The reversal of 256711121 is 121117652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 160376896 + 96334225 = 12664^2 + 9815^2 .

It is a cyclic number.

It is not a de Polignac number, because 256711121 - 2¹⁸ = 256448977 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (256711111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128355560 + 128355561.

It is an arithmetic number, because the mean of its divisors is an integer number (128355561).

Almost surely, 2^256711121 is an apocalyptic number.

It is an amenable number.

256711121 is a deficient number, since it is larger than the sum of its proper divisors (1).

256711121 is an equidigital number, since it uses as much as digits as its factorization.

256711121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 840, while the sum is 26.

The square root of 256711121 is about 16022.2071201193. The cubic root of 256711121 is about 635.5478117259.

Adding to 256711121 its reverse (121117652), we get a palindrome (377828773).

The spelling of 256711121 in words is "two hundred fifty-six million, seven hundred eleven thousand, one hundred twenty-one".