256918477 has 2 divisors, whose sum is σ = 256918478. Its totient is φ = 256918476.

The previous prime is 256918451. The next prime is 256918489. The reversal of 256918477 is 774819652.

256918477 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 242923396 + 13995081 = 15586^2 + 3741^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256918477 is a prime.

It is a super-3 number, since 3×256918477³ (a number of 26 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 256918477.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256918427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128459238 + 128459239.

It is an arithmetic number, because the mean of its divisors is an integer number (128459239).

Almost surely, 2^256918477 is an apocalyptic number.

It is an amenable number.

256918477 is a deficient number, since it is larger than the sum of its proper divisors (1).

256918477 is an equidigital number, since it uses as much as digits as its factorization.

256918477 is an evil number, because the sum of its binary digits is even.

The product of its digits is 846720, while the sum is 49.

The square root of 256918477 is about 16028.6767077011. The cubic root of 256918477 is about 635.7188849344.

The spelling of 256918477 in words is "two hundred fifty-six million, nine hundred eighteen thousand, four hundred seventy-seven".