1247662643 has 2 divisors, whose sum is σ = 1247662644. Its totient is φ = 1247662642.

The previous prime is 1247662639. The next prime is 1247662667. The reversal of 1247662643 is 3462667421.

It is a weak prime.

It is an emirp because it is prime and its reverse (3462667421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1247662643 - 2² = 1247662639 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1247662643.

It is not a weakly prime, because it can be changed into another prime (1247662343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 623831321 + 623831322.

It is an arithmetic number, because the mean of its divisors is an integer number (623831322).

Almost surely, 2^1247662643 is an apocalyptic number.

1247662643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1247662643 is an equidigital number, since it uses as much as digits as its factorization.

1247662643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 290304, while the sum is 41.

The square root of 1247662643 is about 35322.2683727985. The cubic root of 1247662643 is about 1076.5455016845.

The spelling of 1247662643 in words is "one billion, two hundred forty-seven million, six hundred sixty-two thousand, six hundred forty-three".