10021111221 has 24 divisors (see below), whose sum is σ = 14738634400. Its totient is φ = 6051877920.

The previous prime is 10021111187. The next prime is 10021111249. The reversal of 10021111221 is 12211112001.

It is not a de Polignac number, because 10021111221 - 2³⁰ = 8947369397 is a prime.

It is a super-2 number, since 2×10021111221² (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 = 10021111197 and 10021111206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10021111291) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 53955 + ... + 151503.

Almost surely, 2^10021111221 is an apocalyptic number.

10021111221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

10021111221 is a deficient number, since it is larger than the sum of its proper divisors (4717523179).

10021111221 is a wasteful number, since it uses less digits than its factorization.

10021111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97857 (or 97846 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 10021111221 its reverse (12211112001), we get a palindrome (22232223222).

The spelling of 10021111221 in words is "ten billion, twenty-one million, one hundred eleven thousand, two hundred twenty-one".