1247723649 has 16 divisors (see below), whose sum is σ = 1849329600. Its totient is φ = 831433248.

The previous prime is 1247723611. The next prime is 1247723651. The reversal of 1247723649 is 9463277421.

It is a de Polignac number, because none of the positive numbers 2^k-1247723649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1247723549) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56997 + ... + 75789.

It is an arithmetic number, because the mean of its divisors is an integer number (115583100).

Almost surely, 2^1247723649 is an apocalyptic number.

It is an amenable number.

1247723649 is a deficient number, since it is larger than the sum of its proper divisors (601605951).

1247723649 is a wasteful number, since it uses less digits than its factorization.

1247723649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21261 (or 21255 counting only the distinct ones).

The product of its digits is 508032, while the sum is 45.

The square root of 1247723649 is about 35323.1319251280. The cubic root of 1247723649 is about 1076.5630477375.

The spelling of 1247723649 in words is "one billion, two hundred forty-seven million, seven hundred twenty-three thousand, six hundred forty-nine".