1251115345 has 4 divisors (see below), whose sum is σ = 1501338420. Its totient is φ = 1000892272.

The previous prime is 1251115343. The next prime is 1251115351. The reversal of 1251115345 is 5435111521.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 918271809 + 332843536 = 30303^2 + 18244^2 .

It is a cyclic number.

It is not a de Polignac number, because 1251115345 - 2¹ = 1251115343 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1251115343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 125111530 + ... + 125111539.

It is an arithmetic number, because the mean of its divisors is an integer number (375334605).

Almost surely, 2^1251115345 is an apocalyptic number.

It is an amenable number.

1251115345 is a deficient number, since it is larger than the sum of its proper divisors (250223075).

1251115345 is an equidigital number, since it uses as much as digits as its factorization.

1251115345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250223074.

The product of its digits is 3000, while the sum is 28.

The square root of 1251115345 is about 35371.1089026058. The cubic root of 1251115345 is about 1077.5376414984.

Adding to 1251115345 its reverse (5435111521), we get a palindrome (6686226866).

The spelling of 1251115345 in words is "one billion, two hundred fifty-one million, one hundred fifteen thousand, three hundred forty-five".