20221021021 has 4 divisors (see below), whose sum is σ = 21100195872. Its totient is φ = 19341846172.

The previous prime is 20221021001. The next prime is 20221021027. The reversal of 20221021021 is 12012012202.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 20221021021 - 2⁹ = 20221020509 is a prime.

It is a super-2 number, since 2×20221021021² (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 = 20221020992 and 20221021010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20221021027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 439587391 + ... + 439587436.

It is an arithmetic number, because the mean of its divisors is an integer number (5275048968).

Almost surely, 2^20221021021 is an apocalyptic number.

It is an amenable number.

20221021021 is a deficient number, since it is larger than the sum of its proper divisors (879174851).

20221021021 is an equidigital number, since it uses as much as digits as its factorization.

20221021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 879174850.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 20221021021 its reverse (12012012202), we get a palindrome (32233033223).

The spelling of 20221021021 in words is "twenty billion, two hundred twenty-one million, twenty-one thousand, twenty-one".