1251515313 has 32 divisors (see below), whose sum is σ = 1956441600. Its totient is φ = 788503248.

The previous prime is 1251515281. The next prime is 1251515323. The reversal of 1251515313 is 3135151521.

1251515313 is a `hidden beast` number, since 125 + 1 + 5 + 1 + 531 + 3 = 666.

It is not a de Polignac number, because 1251515313 - 2⁵ = 1251515281 is a prime.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1251515323) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 224506 + ... + 230012.

It is an arithmetic number, because the mean of its divisors is an integer number (61138800).

Almost surely, 2^1251515313 is an apocalyptic number.

It is an amenable number.

1251515313 is a deficient number, since it is larger than the sum of its proper divisors (704926287).

1251515313 is a wasteful number, since it uses less digits than its factorization.

1251515313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5978 (or 5972 counting only the distinct ones).

The product of its digits is 2250, while the sum is 27.

The square root of 1251515313 is about 35376.7623306599. The cubic root of 1251515313 is about 1077.6524549617.

Adding to 1251515313 its reverse (3135151521), we get a palindrome (4386666834).

The spelling of 1251515313 in words is "one billion, two hundred fifty-one million, five hundred fifteen thousand, three hundred thirteen".