220121221021 has 8 divisors (see below), whose sum is σ = 237897233784. Its totient is φ = 202465724160.

The previous prime is 220121221003. The next prime is 220121221039. The reversal of 220121221021 is 120122121022.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (220121221003) and next prime (220121221039).

It can be written as a sum of positive squares in 4 ways, for example, as 712356100 + 219408864921 = 26690^2 + 468411^2 .

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 220121221021 - 2¹⁵ = 220121188253 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 220121220986 and 220121221004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220121221121) 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, 30125176 + ... + 30132481.

It is an arithmetic number, because the mean of its divisors is an integer number (29737154223).

Almost surely, 2^220121221021 is an apocalyptic number.

It is an amenable number.

220121221021 is a deficient number, since it is larger than the sum of its proper divisors (17776012763).

220121221021 is a wasteful number, since it uses less digits than its factorization.

220121221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60257951.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 220121221021 its reverse (120122121022), we get a palindrome (340243342043).

Subtracting from 220121221021 its reverse (120122121022), we obtain a palindrome (99999099999).

The spelling of 220121221021 in words is "two hundred twenty billion, one hundred twenty-one million, two hundred twenty-one thousand, twenty-one".