1251292913 has 4 divisors (see below), whose sum is σ = 1347546228. Its totient is φ = 1155039600.

The previous prime is 1251292909. The next prime is 1251292921. The reversal of 1251292913 is 3192921521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3192921521 = 17 ⋅187818913.

It can be written as a sum of positive squares in 2 ways, for example, as 240498064 + 1010794849 = 15508^2 + 31793^2 .

It is not a de Polignac number, because 1251292913 - 2² = 1251292909 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1251292213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48126638 + ... + 48126663.

It is an arithmetic number, because the mean of its divisors is an integer number (336886557).

Almost surely, 2^1251292913 is an apocalyptic number.

1251292913 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1251292913 is a deficient number, since it is larger than the sum of its proper divisors (96253315).

1251292913 is an equidigital number, since it uses as much as digits as its factorization.

1251292913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96253314.

The product of its digits is 9720, while the sum is 35.

The square root of 1251292913 is about 35373.6188846999. The cubic root of 1251292913 is about 1077.5886165886.

The spelling of 1251292913 in words is "one billion, two hundred fifty-one million, two hundred ninety-two thousand, nine hundred thirteen".