21002201 has 12 divisors (see below), whose sum is σ = 24193680. Its totient is φ = 18030960.

The previous prime is 21002129. The next prime is 21002203. The reversal of 21002201 is 10220012.

It is not a de Polignac number, because 21002201 - 2¹⁰ = 21001177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21002203) 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 11 ways as a sum of consecutive naturals, for example, 66095 + ... + 66411.

It is an arithmetic number, because the mean of its divisors is an integer number (2016140).

Almost surely, 2^21002201 is an apocalyptic number.

It is an amenable number.

21002201 is a deficient number, since it is larger than the sum of its proper divisors (3191479).

21002201 is an equidigital number, since it uses as much as digits as its factorization.

21002201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664 (or 347 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 21002201 is about 4582.8158374519. The cubic root of 21002201 is about 275.9020560190.

Adding to 21002201 its reverse (10220012), we get a palindrome (31222213).

The spelling of 21002201 in words is "twenty-one million, two thousand, two hundred one".