221100211212021 has 6 divisors (see below), whose sum is σ = 319366971750710. Its totient is φ = 147400140808008.

The previous prime is 221100211212011. The next prime is 221100211212037. The reversal of 221100211212021 is 120212112001122.

221100211212021 is a `hidden beast` number, since 221 + 1 + 0 + 0 + 211 + 212 + 0 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 213614301802500 + 7485909409521 = 14615550^2 + 2736039^2 .

It is not a de Polignac number, because 221100211212021 - 2³⁸ = 220825333305077 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221100211211985 and 221100211212003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221100211212011) 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, 12283345067326 + ... + 12283345067343.

Almost surely, 2^{221100211212021} is an apocalyptic number.

It is an amenable number.

221100211212021 is a deficient number, since it is larger than the sum of its proper divisors (98266760538689).

221100211212021 is a wasteful number, since it uses less digits than its factorization.

221100211212021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24566690134675 (or 24566690134672 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 221100211212021 its reverse (120212112001122), we get a palindrome (341312323213143).

The spelling of 221100211212021 in words is "two hundred twenty-one trillion, one hundred billion, two hundred eleven million, two hundred twelve thousand, twenty-one".