221001213 has 4 divisors (see below), whose sum is σ = 294668288. Its totient is φ = 147334140.

The previous prime is 221001167. The next prime is 221001223. The reversal of 221001213 is 312100122.

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 221001213 - 2⁸ = 221000957 is a prime.

It is a super-2 number, since 2×221001213² = 97683072294942738, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221001223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36833533 + ... + 36833538.

It is an arithmetic number, because the mean of its divisors is an integer number (73667072).

Almost surely, 2^221001213 is an apocalyptic number.

It is an amenable number.

221001213 is a deficient number, since it is larger than the sum of its proper divisors (73667075).

221001213 is an equidigital number, since it uses as much as digits as its factorization.

221001213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73667074.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 221001213 is about 14866.1095448675. The cubic root of 221001213 is about 604.5954657425.

Adding to 221001213 its reverse (312100122), we get a palindrome (533101335).

The spelling of 221001213 in words is "two hundred twenty-one million, one thousand, two hundred thirteen".