18272215649 has 2 divisors, whose sum is σ = 18272215650. Its totient is φ = 18272215648.

The previous prime is 18272215613. The next prime is 18272215667. The reversal of 18272215649 is 94651227281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17480806225 + 791409424 = 132215^2 + 28132^2 .

It is a cyclic number.

It is not a de Polignac number, because 18272215649 - 2²⁰ = 18271167073 is a prime.

It is not a weakly prime, because it can be changed into another prime (18272215249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9136107824 + 9136107825.

It is an arithmetic number, because the mean of its divisors is an integer number (9136107825).

Almost surely, 2^18272215649 is an apocalyptic number.

It is an amenable number.

18272215649 is a deficient number, since it is larger than the sum of its proper divisors (1).

18272215649 is an equidigital number, since it uses as much as digits as its factorization.

18272215649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 483840, while the sum is 47.

The spelling of 18272215649 in words is "eighteen billion, two hundred seventy-two million, two hundred fifteen thousand, six hundred forty-nine".