221220013 has 4 divisors (see below), whose sum is σ = 252822880. Its totient is φ = 189617148.

The previous prime is 221220007. The next prime is 221220037. The reversal of 221220013 is 310022122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 221220013 - 2¹⁷ = 221088941 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221219975 and 221220002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221220313) 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, 15801423 + ... + 15801436.

It is an arithmetic number, because the mean of its divisors is an integer number (63205720).

Almost surely, 2^221220013 is an apocalyptic number.

It is an amenable number.

221220013 is a deficient number, since it is larger than the sum of its proper divisors (31602867).

221220013 is an equidigital number, since it uses as much as digits as its factorization.

221220013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31602866.

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

The square root of 221220013 is about 14873.4667445085. The cubic root of 221220013 is about 604.7949244606.

Adding to 221220013 its reverse (310022122), we get a palindrome (531242135).

The spelling of 221220013 in words is "two hundred twenty-one million, two hundred twenty thousand, thirteen".