21211110031 has 16 divisors (see below), whose sum is σ = 21621206880. Its totient is φ = 20805537280.

The previous prime is 21211110029. The next prime is 21211110061. The reversal of 21211110031 is 13001111212.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21211110031 - 2¹ = 21211110029 is a prime.

It is a super-2 number, since 2×21211110031² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21211109993 and 21211110020.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211110061) 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 15 ways as a sum of consecutive naturals, for example, 6074196 + ... + 6077686.

It is an arithmetic number, because the mean of its divisors is an integer number (1351325430).

Almost surely, 2^21211110031 is an apocalyptic number.

21211110031 is a deficient number, since it is larger than the sum of its proper divisors (410096849).

21211110031 is a wasteful number, since it uses less digits than its factorization.

21211110031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4106.

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 21211110031 its reverse (13001111212), we get a palindrome (34212221243).

The spelling of 21211110031 in words is "twenty-one billion, two hundred eleven million, one hundred ten thousand, thirty-one".