22001001021 has 12 divisors (see below), whose sum is σ = 32554327260. Its totient is φ = 14309593920.

The previous prime is 22001001019. The next prime is 22001001023. The reversal of 22001001021 is 12010010022.

It is an interprime number because it is at equal distance from previous prime (22001001019) and next prime (22001001023).

It can be written as a sum of positive squares in 2 ways, for example, as 7099916121 + 14901084900 = 84261^2 + 122070^2 .

It is not a de Polignac number, because 22001001021 - 2¹ = 22001001019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 22001000994 and 22001001012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22001001023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29811286 + ... + 29812023.

It is an arithmetic number, because the mean of its divisors is an integer number (2712860605).

Almost surely, 2^22001001021 is an apocalyptic number.

It is an amenable number.

22001001021 is a deficient number, since it is larger than the sum of its proper divisors (10553326239).

22001001021 is a wasteful number, since it uses less digits than its factorization.

22001001021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59623356 (or 59623353 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 22001001021 its reverse (12010010022), we get a palindrome (34011011043).

Subtracting from 22001001021 its reverse (12010010022), we obtain a palindrome (9990990999).

The spelling of 22001001021 in words is "twenty-two billion, one million, one thousand, twenty-one".