256402412489 has 2 divisors, whose sum is σ = 256402412490. Its totient is φ = 256402412488.

The previous prime is 256402412449. The next prime is 256402412491. The reversal of 256402412489 is 984214204652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 174960668089 + 81441744400 = 418283^2 + 285380^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256402412489 is a prime.

Together with 256402412491, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (256402412449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128201206244 + 128201206245.

It is an arithmetic number, because the mean of its divisors is an integer number (128201206245).

Almost surely, 2^256402412489 is an apocalyptic number.

It is an amenable number.

256402412489 is a deficient number, since it is larger than the sum of its proper divisors (1).

256402412489 is an equidigital number, since it uses as much as digits as its factorization.

256402412489 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1105920, while the sum is 47.

The spelling of 256402412489 in words is "two hundred fifty-six billion, four hundred two million, four hundred twelve thousand, four hundred eighty-nine".