1249645391 has 8 divisors (see below), whose sum is σ = 1253702400. Its totient is φ = 1245595680.

The previous prime is 1249645387. The next prime is 1249645399. The reversal of 1249645391 is 1935469421.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1249645391 - 2² = 1249645387 is a prime.

It is a super-2 number, since 2×1249645391² = 3123227206495085762, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1249645399) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 747905 + ... + 749573.

It is an arithmetic number, because the mean of its divisors is an integer number (156712800).

Almost surely, 2^1249645391 is an apocalyptic number.

1249645391 is a deficient number, since it is larger than the sum of its proper divisors (4057009).

1249645391 is a wasteful number, since it uses less digits than its factorization.

1249645391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3649.

The product of its digits is 233280, while the sum is 44.

The square root of 1249645391 is about 35350.3237750378. The cubic root of 1249645391 is about 1077.1154711244.

The spelling of 1249645391 in words is "one billion, two hundred forty-nine million, six hundred forty-five thousand, three hundred ninety-one".