21111221100231 has 6 divisors (see below), whose sum is σ = 30493986033680. Its totient is φ = 14074147400148.

The previous prime is 21111221100169. The next prime is 21111221100239. The reversal of 21111221100231 is 13200112211112.

It is a happy number.

21111221100231 is a `hidden beast` number, since 2 + 1 + 111 + 221 + 100 + 231 = 666.

It is not a de Polignac number, because 21111221100231 - 2⁷ = 21111221100103 is a prime.

It is a super-2 number, since 2×21111221100231² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111221100239) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1172845616671 + ... + 1172845616688.

Almost surely, 2^{21111221100231} is an apocalyptic number.

21111221100231 is a deficient number, since it is larger than the sum of its proper divisors (9382764933449).

21111221100231 is a wasteful number, since it uses less digits than its factorization.

21111221100231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2345691233365 (or 2345691233362 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 18.

Adding to 21111221100231 its reverse (13200112211112), we get a palindrome (34311333311343).

The spelling of 21111221100231 in words is "twenty-one trillion, one hundred eleven billion, two hundred twenty-one million, one hundred thousand, two hundred thirty-one".