18747969217 has 2 divisors, whose sum is σ = 18747969218. Its totient is φ = 18747969216.

The previous prime is 18747969209. The next prime is 18747969259. The reversal of 18747969217 is 71296974781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11413930896 + 7334038321 = 106836^2 + 85639^2 .

It is a cyclic number.

It is not a de Polignac number, because 18747969217 - 2³ = 18747969209 is a prime.

It is not a weakly prime, because it can be changed into another prime (18747969817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9373984608 + 9373984609.

It is an arithmetic number, because the mean of its divisors is an integer number (9373984609).

Almost surely, 2^18747969217 is an apocalyptic number.

It is an amenable number.

18747969217 is a deficient number, since it is larger than the sum of its proper divisors (1).

18747969217 is an equidigital number, since it uses as much as digits as its factorization.

18747969217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10668672, while the sum is 61.

The spelling of 18747969217 in words is "eighteen billion, seven hundred forty-seven million, nine hundred sixty-nine thousand, two hundred seventeen".