18649721983 has 2 divisors, whose sum is σ = 18649721984. Its totient is φ = 18649721982.

The previous prime is 18649721977. The next prime is 18649722019. The reversal of 18649721983 is 38912794681.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18649721983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18649721963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9324860991 + 9324860992.

It is an arithmetic number, because the mean of its divisors is an integer number (9324860992).

Almost surely, 2^18649721983 is an apocalyptic number.

18649721983 is a deficient number, since it is larger than the sum of its proper divisors (1).

18649721983 is an equidigital number, since it uses as much as digits as its factorization.

18649721983 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5225472, while the sum is 58.

The spelling of 18649721983 in words is "eighteen billion, six hundred forty-nine million, seven hundred twenty-one thousand, nine hundred eighty-three".