18649371076549 has 2 divisors, whose sum is σ = 18649371076550. Its totient is φ = 18649371076548.

The previous prime is 18649371076547. The next prime is 18649371076579. The reversal of 18649371076549 is 94567017394681.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15669801420100 + 2979569656449 = 3958510^2 + 1726143^2 .

It is a cyclic number.

It is not a de Polignac number, because 18649371076549 - 2¹ = 18649371076547 is a prime.

Together with 18649371076547, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18649371076547) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9324685538274 + 9324685538275.

It is an arithmetic number, because the mean of its divisors is an integer number (9324685538275).

Almost surely, 2^{18649371076549} is an apocalyptic number.

It is an amenable number.

18649371076549 is a deficient number, since it is larger than the sum of its proper divisors (1).

18649371076549 is an equidigital number, since it uses as much as digits as its factorization.

18649371076549 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 274337280, while the sum is 70.

The spelling of 18649371076549 in words is "eighteen trillion, six hundred forty-nine billion, three hundred seventy-one million, seventy-six thousand, five hundred forty-nine".