256345553 has 2 divisors, whose sum is σ = 256345554. Its totient is φ = 256345552.

The previous prime is 256345519. The next prime is 256345591. The reversal of 256345553 is 355543652.

It is an a-pointer prime, because the next prime (256345591) can be obtained adding 256345553 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 238764304 + 17581249 = 15452^2 + 4193^2 .

It is a cyclic number.

It is not a de Polignac number, because 256345553 - 2¹² = 256341457 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (256345513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128172776 + 128172777.

It is an arithmetic number, because the mean of its divisors is an integer number (128172777).

Almost surely, 2^256345553 is an apocalyptic number.

It is an amenable number.

256345553 is a deficient number, since it is larger than the sum of its proper divisors (1).

256345553 is an equidigital number, since it uses as much as digits as its factorization.

256345553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 270000, while the sum is 38.

The square root of 256345553 is about 16010.7948896986. The cubic root of 256345553 is about 635.2459856702.

The spelling of 256345553 in words is "two hundred fifty-six million, three hundred forty-five thousand, five hundred fifty-three".