21110121999 has 6 divisors (see below), whose sum is σ = 30492398456. Its totient is φ = 14073414660.

The previous prime is 21110121983. The next prime is 21110122003. The reversal of 21110121999 is 99912101112.

It is not a de Polignac number, because 21110121999 - 2⁴ = 21110121983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110121899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1172784547 + ... + 1172784564.

Almost surely, 2^21110121999 is an apocalyptic number.

21110121999 is a deficient number, since it is larger than the sum of its proper divisors (9382276457).

21110121999 is a wasteful number, since it uses less digits than its factorization.

21110121999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2345569117 (or 2345569114 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 36.

The spelling of 21110121999 in words is "twenty-one billion, one hundred ten million, one hundred twenty-one thousand, nine hundred ninety-nine".