1251326313 has 14 divisors (see below), whose sum is σ = 1876132314. Its totient is φ = 834217056.

The previous prime is 1251326309. The next prime is 1251326357. The reversal of 1251326313 is 3136231521.

1251326313 is a `hidden beast` number, since 1 + 25 + 1 + 3 + 2 + 631 + 3 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1192528089 + 58798224 = 34533^2 + 7668^2 .

It is not a de Polignac number, because 1251326313 - 2² = 1251326309 is a prime.

It is a super-3 number, since 3×1251326313³ (a number of 28 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1251326513) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 857520 + ... + 858977.

It is an arithmetic number, because the mean of its divisors is an integer number (134009451).

Almost surely, 2^1251326313 is an apocalyptic number.

It is an amenable number.

1251326313 is a deficient number, since it is larger than the sum of its proper divisors (624806001).

1251326313 is an frugal number, since it uses more digits than its factorization.

1251326313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1716515 (or 1716500 counting only the distinct ones).

The product of its digits is 3240, while the sum is 27.

The square root of 1251326313 is about 35374.0909847872. The cubic root of 1251326313 is about 1077.5982043090.

Adding to 1251326313 its reverse (3136231521), we get a palindrome (4387557834).

The spelling of 1251326313 in words is "one billion, two hundred fifty-one million, three hundred twenty-six thousand, three hundred thirteen".