18912121161559 has 2 divisors, whose sum is σ = 18912121161560. Its totient is φ = 18912121161558.

The previous prime is 18912121161547. The next prime is 18912121161587. The reversal of 18912121161559 is 95516112121981.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18912121161559 - 2⁹ = 18912121161047 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18912121161599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9456060580779 + 9456060580780.

It is an arithmetic number, because the mean of its divisors is an integer number (9456060580780).

Almost surely, 2^{18912121161559} is an apocalyptic number.

18912121161559 is a deficient number, since it is larger than the sum of its proper divisors (1).

18912121161559 is an equidigital number, since it uses as much as digits as its factorization.

18912121161559 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 388800, while the sum is 52.

The spelling of 18912121161559 in words is "eighteen trillion, nine hundred twelve billion, one hundred twenty-one million, one hundred sixty-one thousand, five hundred fifty-nine".