21111210999999 has 24 divisors (see below), whose sum is σ = 32112231465600. Its totient is φ = 13327865925840.

The previous prime is 21111210999821. The next prime is 21111211000039. The reversal of 21111210999999 is 99999901211112.

It is not a de Polignac number, because 21111210999999 - 2¹¹ = 21111210997951 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111210999199) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25190659 + ... + 26015220.

It is an arithmetic number, because the mean of its divisors is an integer number (1338009644400).

Almost surely, 2^{21111210999999} is an apocalyptic number.

21111210999999 is a deficient number, since it is larger than the sum of its proper divisors (11001020465601).

21111210999999 is a wasteful number, since it uses less digits than its factorization.

21111210999999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51208315 (or 51208312 counting only the distinct ones).

The product of its (nonzero) digits is 2125764, while the sum is 63.

The spelling of 21111210999999 in words is "twenty-one trillion, one hundred eleven billion, two hundred ten million, nine hundred ninety-nine thousand, nine hundred ninety-nine".