21001122121011 has 8 divisors (see below), whose sum is σ = 28028655715584. Its totient is φ = 13987168303560.

The previous prime is 21001122120943. The next prime is 21001122121079. The reversal of 21001122121011 is 11012122110012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21001122120943) and next prime (21001122121079).

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

It is not a de Polignac number, because 21001122121011 - 2²⁷ = 21000987903283 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21001122821011) 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, 3394940671 + ... + 3394946856.

It is an arithmetic number, because the mean of its divisors is an integer number (3503581964448).

Almost surely, 2^{21001122121011} is an apocalyptic number.

21001122121011 is a deficient number, since it is larger than the sum of its proper divisors (7027533594573).

21001122121011 is a wasteful number, since it uses less digits than its factorization.

21001122121011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6789888561.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21001122121011 its reverse (11012122110012), we get a palindrome (32013244231023).

The spelling of 21001122121011 in words is "twenty-one trillion, one billion, one hundred twenty-two million, one hundred twenty-one thousand, eleven".