2556540257 has 4 divisors (see below), whose sum is σ = 2706924996. Its totient is φ = 2406155520.

The previous prime is 2556540221. The next prime is 2556540263. The reversal of 2556540257 is 7520456552.

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 958459681 + 1598080576 = 30959^2 + 39976^2 .

It is not a de Polignac number, because 2556540257 - 2¹² = 2556536161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2556740257) 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, 75192344 + ... + 75192377.

It is an arithmetic number, because the mean of its divisors is an integer number (676731249).

Almost surely, 2^2556540257 is an apocalyptic number.

It is an amenable number.

2556540257 is a deficient number, since it is larger than the sum of its proper divisors (150384739).

2556540257 is a wasteful number, since it uses less digits than its factorization.

2556540257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150384738.

The product of its (nonzero) digits is 420000, while the sum is 41.

The square root of 2556540257 is about 50562.2414159024. The cubic root of 2556540257 is about 1367.3642214630.

The spelling of 2556540257 in words is "two billion, five hundred fifty-six million, five hundred forty thousand, two hundred fifty-seven".