17994501643 has 2 divisors, whose sum is σ = 17994501644. Its totient is φ = 17994501642.

The previous prime is 17994501631. The next prime is 17994501659. The reversal of 17994501643 is 34610549971.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-17994501643 is a prime.

It is not a weakly prime, because it can be changed into another prime (17994504643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8997250821 + 8997250822.

It is an arithmetic number, because the mean of its divisors is an integer number (8997250822).

Almost surely, 2^17994501643 is an apocalyptic number.

17994501643 is a deficient number, since it is larger than the sum of its proper divisors (1).

17994501643 is an equidigital number, since it uses as much as digits as its factorization.

17994501643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 816480, while the sum is 49.

The spelling of 17994501643 in words is "seventeen billion, nine hundred ninety-four million, five hundred one thousand, six hundred forty-three".