1257868049 has 4 divisors (see below), whose sum is σ = 1264253364. Its totient is φ = 1251482736.

The previous prime is 1257868019. The next prime is 1257868067. The reversal of 1257868049 is 9408687521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9408687521 = 173 ⋅54385477.

It can be written as a sum of positive squares in 2 ways, for example, as 626250625 + 631617424 = 25025^2 + 25132^2 .

It is a cyclic number.

It is not a de Polignac number, because 1257868049 - 2²⁸ = 989432593 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1257867988 and 1257868006.

It is not an unprimeable number, because it can be changed into a prime (1257868019) 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, 3192362 + ... + 3192755.

It is an arithmetic number, because the mean of its divisors is an integer number (316063341).

Almost surely, 2^1257868049 is an apocalyptic number.

It is an amenable number.

1257868049 is a deficient number, since it is larger than the sum of its proper divisors (6385315).

1257868049 is an equidigital number, since it uses as much as digits as its factorization.

1257868049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6385314.

The product of its (nonzero) digits is 967680, while the sum is 50.

The square root of 1257868049 is about 35466.4355271290. The cubic root of 1257868049 is about 1079.4727790781.

The spelling of 1257868049 in words is "one billion, two hundred fifty-seven million, eight hundred sixty-eight thousand, forty-nine".