220810621 has 4 divisors (see below), whose sum is σ = 220841244. Its totient is φ = 220780000.

The previous prime is 220810591. The next prime is 220810631. The reversal of 220810621 is 126018022.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 24502500 + 196308121 = 4950^2 + 14011^2 .

It is a cyclic number.

It is not a de Polignac number, because 220810621 - 2⁵ = 220810589 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 220810592 and 220810601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220810631) 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, 2121 + ... + 21121.

It is an arithmetic number, because the mean of its divisors is an integer number (55210311).

Almost surely, 2^220810621 is an apocalyptic number.

It is an amenable number.

220810621 is a deficient number, since it is larger than the sum of its proper divisors (30623).

220810621 is a wasteful number, since it uses less digits than its factorization.

220810621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30622.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 220810621 is about 14859.6978771441. The cubic root of 220810621 is about 604.4216142079.

Adding to 220810621 its reverse (126018022), we get a palindrome (346828643).

The spelling of 220810621 in words is "two hundred twenty million, eight hundred ten thousand, six hundred twenty-one".