221221003 has 4 divisors (see below), whose sum is σ = 221377888. Its totient is φ = 221064120.

The previous prime is 221220997. The next prime is 221221037. The reversal of 221221003 is 300122122.

221221003 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 300122122 = 2 ⋅150061061.

It is a cyclic number.

It is not a de Polignac number, because 221221003 - 2⁹ = 221220491 is a prime.

It is a super-3 number, since 3×221221003³ (a number of 26 digits) contains 333 as substring.

It is the 14874-th Hogben number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221221073) by changing a digit.

It is a nontrivial repunit in base 14873.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76308 + ... + 79153.

It is an arithmetic number, because the mean of its divisors is an integer number (55344472).

Almost surely, 2^221221003 is an apocalyptic number.

221221003 is a deficient number, since it is larger than the sum of its proper divisors (156885).

221221003 is a wasteful number, since it uses less digits than its factorization.

221221003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156884.

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

The square root of 221221003 is about 14873.5000252126. The cubic root of 221221003 is about 604.7958266485.

Adding to 221221003 its reverse (300122122), we get a palindrome (521343125).

It can be divided in two parts, 22 and 1221003, that added together give a square (1221025 = 1105²).

The spelling of 221221003 in words is "two hundred twenty-one million, two hundred twenty-one thousand, three".