220121210021 has 8 divisors (see below), whose sum is σ = 222313268088. Its totient is φ = 217929400000.

The previous prime is 220121210011. The next prime is 220121210027. The reversal of 220121210021 is 120012121022.

It can be written as a sum of positive squares in 4 ways, for example, as 160709584996 + 59411625025 = 400886^2 + 243745^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 220121210021 - 2³⁰ = 219047468197 is a prime.

It is a super-2 number, since 2×220121210021² (a number of 23 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 = 220121209978 and 220121210005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220121210027) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2091971 + ... + 2194671.

It is an arithmetic number, because the mean of its divisors is an integer number (27789158511).

Almost surely, 2^220121210021 is an apocalyptic number.

It is an amenable number.

220121210021 is a deficient number, since it is larger than the sum of its proper divisors (2192058067).

220121210021 is a wasteful number, since it uses less digits than its factorization.

220121210021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124023.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 220121210021 its reverse (120012121022), we get a palindrome (340133331043).

The spelling of 220121210021 in words is "two hundred twenty billion, one hundred twenty-one million, two hundred ten thousand, twenty-one".