1249999999 has 4 divisors (see below), whose sum is σ = 1250287920. Its totient is φ = 1249712080.

The previous prime is 1249999997. The next prime is 1250000027. The reversal of 1249999999 is 9999999421.

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

It is a cyclic number.

It is not a de Polignac number, because 1249999999 - 2¹ = 1249999997 is a prime.

It is a Duffinian number.

1249999999 is a modest number, since divided by 99999 gives 12499 as remainder.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1249999991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 137347 + ... + 146164.

It is an arithmetic number, because the mean of its divisors is an integer number (312571980).

Almost surely, 2^1249999999 is an apocalyptic number.

1249999999 is a deficient number, since it is larger than the sum of its proper divisors (287921).

1249999999 is an equidigital number, since it uses as much as digits as its factorization.

1249999999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287920.

The product of its digits is 38263752, while the sum is 70.

The square root of 1249999999 is about 35355.3390451852. The cubic root of 1249999999 is about 1077.2173447287.

The spelling of 1249999999 in words is "one billion, two hundred forty-nine million, nine hundred ninety-nine thousand, nine hundred ninety-nine".