21211112091 has 24 divisors (see below), whose sum is σ = 30827248896. Its totient is φ = 12966501600.

The previous prime is 21211112017. The next prime is 21211112147. The reversal of 21211112091 is 19021111212.

It is not a de Polignac number, because 21211112091 - 2⁷ = 21211111963 is a prime.

It is a super-2 number, since 2×21211112091² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21211112191) 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, 61975 + ... + 215088.

It is an arithmetic number, because the mean of its divisors is an integer number (1284468704).

Almost surely, 2^21211112091 is an apocalyptic number.

21211112091 is a deficient number, since it is larger than the sum of its proper divisors (9616136805).

21211112091 is a wasteful number, since it uses less digits than its factorization.

21211112091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277243 (or 277230 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 21.

The spelling of 21211112091 in words is "twenty-one billion, two hundred eleven million, one hundred twelve thousand, ninety-one".