221012210220021 has 18 divisors (see below), whose sum is σ = 350900010534710. Its totient is φ = 133946794072080.

The previous prime is 221012210219959. The next prime is 221012210220079. The reversal of 221012210220021 is 120022012210122.

It is a happy number.

221012210220021 is a `hidden beast` number, since 2 + 210 + 1 + 2 + 210 + 220 + 0 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 220512699108900 + 499511111121 = 14849670^2 + 706761^2 .

It is not a de Polignac number, because 221012210220021 - 2¹⁴ = 221012210203637 is a prime.

It is a super-2 number, since 2×221012210220021² (a number of 29 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 = 221012210219976 and 221012210220003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221012210220421) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 101474842906 + ... + 101474845083.

Almost surely, 2^{221012210220021} is an apocalyptic number.

It is an amenable number.

221012210220021 is a deficient number, since it is larger than the sum of its proper divisors (129887800314689).

221012210220021 is a wasteful number, since it uses less digits than its factorization.

221012210220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202949688017 (or 202949688003 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 221012210220021 its reverse (120022012210122), we get a palindrome (341034222430143).

The spelling of 221012210220021 in words is "two hundred twenty-one trillion, twelve billion, two hundred ten million, two hundred twenty thousand, twenty-one".