220331021 has 4 divisors (see below), whose sum is σ = 220366044. Its totient is φ = 220296000.

The previous prime is 220331003. The next prime is 220331039. The reversal of 220331021 is 120133022.

It is a happy number.

220331021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is an interprime number because it is at equal distance from previous prime (220331003) and next prime (220331039).

It can be written as a sum of positive squares in 2 ways, for example, as 149181796 + 71149225 = 12214^2 + 8435^2 .

It is a cyclic number.

It is not a de Polignac number, because 220331021 - 2¹⁴ = 220314637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 220330987 and 220331005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220331081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5180 + ... + 21621.

It is an arithmetic number, because the mean of its divisors is an integer number (55091511).

Almost surely, 2^220331021 is an apocalyptic number.

It is an amenable number.

220331021 is a deficient number, since it is larger than the sum of its proper divisors (35023).

220331021 is an equidigital number, since it uses as much as digits as its factorization.

220331021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35022.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 220331021 is about 14843.5514955148. The cubic root of 220331021 is about 603.9836963642.

Adding to 220331021 its reverse (120133022), we get a palindrome (340464043).

The spelling of 220331021 in words is "two hundred twenty million, three hundred thirty-one thousand, twenty-one".