21221100201 has 16 divisors (see below), whose sum is σ = 32947046784. Its totient is φ = 11897543424.

The previous prime is 21221100163. The next prime is 21221100223. The reversal of 21221100201 is 10200112212.

It is not a de Polignac number, because 21221100201 - 2¹⁵ = 21221067433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221100101) 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, 9532176 + ... + 9534401.

It is an arithmetic number, because the mean of its divisors is an integer number (2059190424).

Almost surely, 2^21221100201 is an apocalyptic number.

21221100201 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21221100201 is a deficient number, since it is larger than the sum of its proper divisors (11725946583).

21221100201 is a wasteful number, since it uses less digits than its factorization.

21221100201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19066640.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21221100201 its reverse (10200112212), we get a palindrome (31421212413).

The spelling of 21221100201 in words is "twenty-one billion, two hundred twenty-one million, one hundred thousand, two hundred one".