256598621 has 2 divisors, whose sum is σ = 256598622. Its totient is φ = 256598620.

The previous prime is 256598609. The next prime is 256598653. The reversal of 256598621 is 126895652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 239042521 + 17556100 = 15461^2 + 4190^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256598621 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256598821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128299310 + 128299311.

It is an arithmetic number, because the mean of its divisors is an integer number (128299311).

Almost surely, 2^256598621 is an apocalyptic number.

It is an amenable number.

256598621 is a deficient number, since it is larger than the sum of its proper divisors (1).

256598621 is an equidigital number, since it uses as much as digits as its factorization.

256598621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 259200, while the sum is 44.

The square root of 256598621 is about 16018.6959831317. The cubic root of 256598621 is about 635.4549582290.

The spelling of 256598621 in words is "two hundred fifty-six million, five hundred ninety-eight thousand, six hundred twenty-one".