221020313 has 4 divisors (see below), whose sum is σ = 224766480. Its totient is φ = 217274148.

The previous prime is 221020279. The next prime is 221020321. The reversal of 221020313 is 313020122.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 221020313 - 2⁸ = 221020057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221020333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1872995 + ... + 1873112.

It is an arithmetic number, because the mean of its divisors is an integer number (56191620).

Almost surely, 2^221020313 is an apocalyptic number.

It is an amenable number.

221020313 is a deficient number, since it is larger than the sum of its proper divisors (3746167).

221020313 is an equidigital number, since it uses as much as digits as its factorization.

221020313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3746166.

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

The square root of 221020313 is about 14866.7519317435. The cubic root of 221020313 is about 604.6128826012.

Adding to 221020313 its reverse (313020122), we get a palindrome (534040435).

The spelling of 221020313 in words is "two hundred twenty-one million, twenty thousand, three hundred thirteen".