21020121022 has 4 divisors (see below), whose sum is σ = 31530181536. Its totient is φ = 10510060510.

The previous prime is 21020121007. The next prime is 21020121029. The reversal of 21020121022 is 22012102012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 21020120993 and 21020121011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020121029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5255030254 + ... + 5255030257.

It is an arithmetic number, because the mean of its divisors is an integer number (7882545384).

Almost surely, 2^21020121022 is an apocalyptic number.

21020121022 is a deficient number, since it is larger than the sum of its proper divisors (10510060514).

21020121022 is a wasteful number, since it uses less digits than its factorization.

21020121022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10510060513.

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

Adding to 21020121022 its reverse (22012102012), we get a palindrome (43032223034).

The spelling of 21020121022 in words is "twenty-one billion, twenty million, one hundred twenty-one thousand, twenty-two".