21221012211 has 16 divisors (see below), whose sum is σ = 33379903488. Its totient is φ = 11735121600.

The previous prime is 21221012209. The next prime is 21221012213. The reversal of 21221012211 is 11221012212.

It is an interprime number because it is at equal distance from previous prime (21221012209) and next prime (21221012213).

It is not a de Polignac number, because 21221012211 - 2¹ = 21221012209 is a prime.

It is a super-2 number, since 2×21221012211² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21221012213) 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, 16298130 + ... + 16299431.

It is an arithmetic number, because the mean of its divisors is an integer number (2086243968).

Almost surely, 2^21221012211 is an apocalyptic number.

21221012211 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21221012211 is a deficient number, since it is larger than the sum of its proper divisors (12158891277).

21221012211 is a wasteful number, since it uses less digits than its factorization.

21221012211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32597602.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21221012211 its reverse (11221012212), we get a palindrome (32442024423).

Subtracting from 21221012211 its reverse (11221012212), we obtain a palindrome (9999999999).

The spelling of 21221012211 in words is "twenty-one billion, two hundred twenty-one million, twelve thousand, two hundred eleven".