22100021 has 4 divisors (see below), whose sum is σ = 23263200. Its totient is φ = 20936844.

The previous prime is 22099999. The next prime is 22100041. The reversal of 22100021 is 12000122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12000122 = 2 ⋅6000061.

It is a cyclic number.

It is not a de Polignac number, because 22100021 - 2¹⁴ = 22083637 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 22099981 and 22100008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22100041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 581561 + ... + 581598.

It is an arithmetic number, because the mean of its divisors is an integer number (5815800).

Almost surely, 2^22100021 is an apocalyptic number.

It is an amenable number.

22100021 is a deficient number, since it is larger than the sum of its proper divisors (1163179).

22100021 is a wasteful number, since it uses less digits than its factorization.

22100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1163178.

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

The square root of 22100021 is about 4701.0659429538. The cubic root of 22100021 is about 280.6279317257.

Adding to 22100021 its reverse (12000122), we get a palindrome (34100143).

The spelling of 22100021 in words is "twenty-two million, one hundred thousand, twenty-one".