221002221 has 16 divisors (see below), whose sum is σ = 330147648. Its totient is φ = 130320000.

The previous prime is 221002211. The next prime is 221002231. The reversal of 221002221 is 122200122.

It is an interprime number because it is at equal distance from previous prime (221002211) and next prime (221002231).

It is not a de Polignac number, because 221002221 - 2¹⁵ = 220969453 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221002197 and 221002206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221002211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 89280 + ... + 91721.

It is an arithmetic number, because the mean of its divisors is an integer number (20634228).

Almost surely, 2^221002221 is an apocalyptic number.

It is an amenable number.

221002221 is a deficient number, since it is larger than the sum of its proper divisors (109145427).

221002221 is a wasteful number, since it uses less digits than its factorization.

221002221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181052.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 221002221 is about 14866.1434474446. The cubic root of 221002221 is about 604.5963849400.

Adding to 221002221 its reverse (122200122), we get a palindrome (343202343).

The spelling of 221002221 in words is "two hundred twenty-one million, two thousand, two hundred twenty-one".