257939774387 has 2 divisors, whose sum is σ = 257939774388. Its totient is φ = 257939774386.

The previous prime is 257939774383. The next prime is 257939774431. The reversal of 257939774387 is 783477939752.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 257939774387 - 2² = 257939774383 is a prime.

It is a super-2 number, since 2×257939774387² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 257939774387.

It is not a weakly prime, because it can be changed into another prime (257939774383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128969887193 + 128969887194.

It is an arithmetic number, because the mean of its divisors is an integer number (128969887194).

Almost surely, 2^257939774387 is an apocalyptic number.

257939774387 is a deficient number, since it is larger than the sum of its proper divisors (1).

257939774387 is an equidigital number, since it uses as much as digits as its factorization.

257939774387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 560105280, while the sum is 71.

The spelling of 257939774387 in words is "two hundred fifty-seven billion, nine hundred thirty-nine million, seven hundred seventy-four thousand, three hundred eighty-seven".