257679954781 has 4 divisors (see below), whose sum is σ = 260231241564. Its totient is φ = 255128668000.

The previous prime is 257679954769. The next prime is 257679954787. The reversal of 257679954781 is 187459976752.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 146127294756 + 111552660025 = 382266^2 + 333995^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257679954781 is a prime.

It is a super-2 number, since 2×257679954781² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 257679954781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257679954787) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1275643240 + ... + 1275643441.

It is an arithmetic number, because the mean of its divisors is an integer number (65057810391).

Almost surely, 2^257679954781 is an apocalyptic number.

It is an amenable number.

257679954781 is a deficient number, since it is larger than the sum of its proper divisors (2551286783).

257679954781 is a wasteful number, since it uses less digits than its factorization.

257679954781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2551286782.

The product of its digits is 266716800, while the sum is 70.

The spelling of 257679954781 in words is "two hundred fifty-seven billion, six hundred seventy-nine million, nine hundred fifty-four thousand, seven hundred eighty-one".