256220387 has 2 divisors, whose sum is σ = 256220388. Its totient is φ = 256220386.

The previous prime is 256220369. The next prime is 256220399. The reversal of 256220387 is 783022652.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256220387 - 2¹⁶ = 256154851 is a prime.

It is not a weakly prime, because it can be changed into another prime (256220317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128110193 + 128110194.

It is an arithmetic number, because the mean of its divisors is an integer number (128110194).

Almost surely, 2^256220387 is an apocalyptic number.

256220387 is a deficient number, since it is larger than the sum of its proper divisors (1).

256220387 is an equidigital number, since it uses as much as digits as its factorization.

256220387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40320, while the sum is 35.

The square root of 256220387 is about 16006.8856121358. The cubic root of 256220387 is about 635.1425781894.

The spelling of 256220387 in words is "two hundred fifty-six million, two hundred twenty thousand, three hundred eighty-seven".