221664503 has 4 divisors (see below), whose sum is σ = 222206880. Its totient is φ = 221122128.

The previous prime is 221664467. The next prime is 221664511. The reversal of 221664503 is 305466122.

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

It is a cyclic number.

It is not a de Polignac number, because 221664503 - 2¹⁰ = 221663479 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 (221664563) 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, 270575 + ... + 271392.

It is an arithmetic number, because the mean of its divisors is an integer number (55551720).

Almost surely, 2^221664503 is an apocalyptic number.

221664503 is a deficient number, since it is larger than the sum of its proper divisors (542377).

221664503 is an equidigital number, since it uses as much as digits as its factorization.

221664503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 542376.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 221664503 is about 14888.4016267697. The cubic root of 221664503 is about 605.1997182310.

The spelling of 221664503 in words is "two hundred twenty-one million, six hundred sixty-four thousand, five hundred three".