22222222021 has 4 divisors (see below), whose sum is σ = 22222537344. Its totient is φ = 22221906700.

The previous prime is 22222222007. The next prime is 22222222031. The reversal of 22222222021 is 12022222222.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 22222222021 - 2¹⁷ = 22222090949 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 22222222021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22222222031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1836 + ... + 210826.

It is an arithmetic number, because the mean of its divisors is an integer number (5555634336).

Almost surely, 2^22222222021 is an apocalyptic number.

It is an amenable number.

22222222021 is a deficient number, since it is larger than the sum of its proper divisors (315323).

22222222021 is a wasteful number, since it uses less digits than its factorization.

22222222021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315322.

The product of its (nonzero) digits is 512, while the sum is 19.

Adding to 22222222021 its reverse (12022222222), we get a palindrome (34244444243).

The spelling of 22222222021 in words is "twenty-two billion, two hundred twenty-two million, two hundred twenty-two thousand, twenty-one".