21201312111 has 48 divisors (see below), whose sum is σ = 33245995104. Its totient is φ = 11982222336.

The previous prime is 21201312079. The next prime is 21201312133. The reversal of 21201312111 is 11121310212.

It is not a de Polignac number, because 21201312111 - 2⁵ = 21201312079 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201312311) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5898931 + ... + 5902523.

It is an arithmetic number, because the mean of its divisors is an integer number (692624898).

Almost surely, 2^21201312111 is an apocalyptic number.

21201312111 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21201312111 is a deficient number, since it is larger than the sum of its proper divisors (12044682993).

21201312111 is a wasteful number, since it uses less digits than its factorization.

21201312111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4040 (or 4033 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21201312111 its reverse (11121310212), we get a palindrome (32322622323).

The spelling of 21201312111 in words is "twenty-one billion, two hundred one million, three hundred twelve thousand, one hundred eleven".