220021321 has 4 divisors (see below), whose sum is σ = 236946052. Its totient is φ = 203096592.

The previous prime is 220021313. The next prime is 220021337. The reversal of 220021321 is 123120022.

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

It can be written as a sum of positive squares in 2 ways, for example, as 65367225 + 154654096 = 8085^2 + 12436^2 .

It is a cyclic number.

It is not a de Polignac number, because 220021321 - 2³ = 220021313 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 16924717 = 220021321 / (2 + 2 + 0 + 0 + 2 + 1 + 3 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (220021301) 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, 8462346 + ... + 8462371.

It is an arithmetic number, because the mean of its divisors is an integer number (59236513).

Almost surely, 2^220021321 is an apocalyptic number.

It is an amenable number.

220021321 is a deficient number, since it is larger than the sum of its proper divisors (16924731).

220021321 is a wasteful number, since it uses less digits than its factorization.

220021321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16924730.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 220021321 is about 14833.1156875418. The cubic root of 220021321 is about 603.7005746925.

Adding to 220021321 its reverse (123120022), we get a palindrome (343141343).

The spelling of 220021321 in words is "two hundred twenty million, twenty-one thousand, three hundred twenty-one".