1251231313 has 2 divisors, whose sum is σ = 1251231314. Its totient is φ = 1251231312.

The previous prime is 1251231307. The next prime is 1251231343. The reversal of 1251231313 is 3131321521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 755590144 + 495641169 = 27488^2 + 22263^2 .

It is a cyclic number.

It is not a de Polignac number, because 1251231313 - 2⁵ = 1251231281 is a prime.

It is not a weakly prime, because it can be changed into another prime (1251231343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625615656 + 625615657.

It is an arithmetic number, because the mean of its divisors is an integer number (625615657).

Almost surely, 2^1251231313 is an apocalyptic number.

It is an amenable number.

1251231313 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251231313 is an equidigital number, since it uses as much as digits as its factorization.

1251231313 is an evil number, because the sum of its binary digits is even.

The product of its digits is 540, while the sum is 22.

The square root of 1251231313 is about 35372.7481686114. The cubic root of 1251231313 is about 1077.5709333994.

Adding to 1251231313 its reverse (3131321521), we get a palindrome (4382552834).

The spelling of 1251231313 in words is "one billion, two hundred fifty-one million, two hundred thirty-one thousand, three hundred thirteen".