21101111188 has 12 divisors (see below), whose sum is σ = 37785711040. Its totient is φ = 10305193752.

The previous prime is 21101111173. The next prime is 21101111189. The reversal of 21101111188 is 88111110112.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101111189) 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 in 3 ways as a sum of consecutive naturals, for example, 61340268 + ... + 61340611.

Almost surely, 2^21101111188 is an apocalyptic number.

It is an amenable number.

21101111188 is a deficient number, since it is larger than the sum of its proper divisors (16684599852).

21101111188 is a wasteful number, since it uses less digits than its factorization.

21101111188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122680926 (or 122680924 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 25.

The spelling of 21101111188 in words is "twenty-one billion, one hundred one million, one hundred eleven thousand, one hundred eighty-eight".