1251317263 has 12 divisors (see below), whose sum is σ = 1502571072. Its totient is φ = 1037957760.

The previous prime is 1251317251. The next prime is 1251317269. The reversal of 1251317263 is 3627131521.

It is a happy number.

It is not a de Polignac number, because 1251317263 - 2²⁹ = 714446351 is a prime.

It is a super-2 number, since 2×1251317263² = 3131589785363622338, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1251317269) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 410370 + ... + 413407.

It is an arithmetic number, because the mean of its divisors is an integer number (125214256).

Almost surely, 2^1251317263 is an apocalyptic number.

1251317263 is a deficient number, since it is larger than the sum of its proper divisors (251253809).

1251317263 is an equidigital number, since it uses as much as digits as its factorization.

1251317263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 823822 (or 823815 counting only the distinct ones).

The product of its digits is 7560, while the sum is 31.

The square root of 1251317263 is about 35373.9630660745. The cubic root of 1251317263 is about 1077.5956064555.

Adding to 1251317263 its reverse (3627131521), we get a palindrome (4878448784).

The spelling of 1251317263 in words is "one billion, two hundred fifty-one million, three hundred seventeen thousand, two hundred sixty-three".