21021212211 has 8 divisors (see below), whose sum is σ = 28365973440. Its totient is φ = 13845296232.

The previous prime is 21021212141. The next prime is 21021212221. The reversal of 21021212211 is 11221212012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21021212211 - 2⁷ = 21021212083 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21021212221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42211021 + ... + 42211518.

It is an arithmetic number, because the mean of its divisors is an integer number (3545746680).

Almost surely, 2^21021212211 is an apocalyptic number.

21021212211 is a deficient number, since it is larger than the sum of its proper divisors (7344761229).

21021212211 is an equidigital number, since it uses as much as digits as its factorization.

21021212211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84422625.

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

Adding to 21021212211 its reverse (11221212012), we get a palindrome (32242424223).

The spelling of 21021212211 in words is "twenty-one billion, twenty-one million, two hundred twelve thousand, two hundred eleven".