21021212011 has 32 divisors (see below), whose sum is σ = 23203514880. Its totient is φ = 18966790656.

The previous prime is 21021211987. The next prime is 21021212041. The reversal of 21021212011 is 11021212012.

It is not a de Polignac number, because 21021212011 - 2⁹ = 21021211499 is a prime.

It is a super-2 number, since 2×21021212011² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21021211982 and 21021212000.

It is not an unprimeable number, because it can be changed into a prime (21021212041) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6920185 + ... + 6923221.

It is an arithmetic number, because the mean of its divisors is an integer number (725109840).

Almost surely, 2^21021212011 is an apocalyptic number.

21021212011 is a deficient number, since it is larger than the sum of its proper divisors (2182302869).

21021212011 is a wasteful number, since it uses less digits than its factorization.

21021212011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3283.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21021212011 its reverse (11021212012), we get a palindrome (32042424023).

Subtracting from 21021212011 its reverse (11021212012), we obtain a palindrome (9999999999).

The spelling of 21021212011 in words is "twenty-one billion, twenty-one million, two hundred twelve thousand, eleven".