221349021 has 16 divisors (see below), whose sum is σ = 306862080. Its totient is φ = 141770160.

The previous prime is 221349019. The next prime is 221349043. The reversal of 221349021 is 120943122.

It is not a de Polignac number, because 221349021 - 2¹ = 221349019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221348982 and 221349000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220349021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4366 + ... + 21488.

It is an arithmetic number, because the mean of its divisors is an integer number (19178880).

Almost surely, 2^221349021 is an apocalyptic number.

It is an amenable number.

221349021 is a deficient number, since it is larger than the sum of its proper divisors (85513059).

221349021 is a wasteful number, since it uses less digits than its factorization.

221349021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17296.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 221349021 is about 14877.8029628033. The cubic root of 221349021 is about 604.9124669026.

The spelling of 221349021 in words is "two hundred twenty-one million, three hundred forty-nine thousand, twenty-one".