221007613 has 4 divisors (see below), whose sum is σ = 223286140. Its totient is φ = 218729088.

The previous prime is 221007571. The next prime is 221007617. The reversal of 221007613 is 316700122.

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 45657049 + 175350564 = 6757^2 + 13242^2 .

It is a cyclic number.

It is not a de Polignac number, because 221007613 - 2¹³ = 220999421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221007617) 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, 1139118 + ... + 1139311.

It is an arithmetic number, because the mean of its divisors is an integer number (55821535).

Almost surely, 2^221007613 is an apocalyptic number.

It is an amenable number.

221007613 is a deficient number, since it is larger than the sum of its proper divisors (2278527).

221007613 is an equidigital number, since it uses as much as digits as its factorization.

221007613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2278526.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 221007613 is about 14866.3247980125. The cubic root of 221007613 is about 604.6013018697.

Adding to 221007613 its reverse (316700122), we get a palindrome (537707735).

The spelling of 221007613 in words is "two hundred twenty-one million, seven thousand, six hundred thirteen".