256400449601 has 2 divisors, whose sum is σ = 256400449602. Its totient is φ = 256400449600.

The previous prime is 256400449567. The next prime is 256400449603. The reversal of 256400449601 is 106944004652.

It is a Cunningham number, because it is equal to 506360²+1.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 256400449600 + 1 = 506360^2 + 1^2 .

It is a cyclic number.

It is not a de Polignac number, because 256400449601 - 2³⁰ = 255326707777 is a prime.

Together with 256400449603, 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 (256400449603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128200224800 + 128200224801.

It is an arithmetic number, because the mean of its divisors is an integer number (128200224801).

Almost surely, 2^256400449601 is an apocalyptic number.

It is an amenable number.

256400449601 is a deficient number, since it is larger than the sum of its proper divisors (1).

256400449601 is an equidigital number, since it uses as much as digits as its factorization.

256400449601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 207360, while the sum is 41.

The spelling of 256400449601 in words is "two hundred fifty-six billion, four hundred million, four hundred forty-nine thousand, six hundred one".