221100201220021 has 16 divisors (see below), whose sum is σ = 234162520704000. Its totient is φ = 208044156619008.

The previous prime is 221100201220001. The next prime is 221100201220039. The reversal of 221100201220021 is 120022102001122.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-221100201220021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221100201219977 and 221100201220004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221100201220001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1489829380 + ... + 1489977778.

It is an arithmetic number, because the mean of its divisors is an integer number (14635157544000).

Almost surely, 2^{221100201220021} is an apocalyptic number.

It is an amenable number.

221100201220021 is a deficient number, since it is larger than the sum of its proper divisors (13062319483979).

221100201220021 is a wasteful number, since it uses less digits than its factorization.

221100201220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168948.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 221100201220021 its reverse (120022102001122), we get a palindrome (341122303221143).

The spelling of 221100201220021 in words is "two hundred twenty-one trillion, one hundred billion, two hundred one million, two hundred twenty thousand, twenty-one".