21121101206 has 16 divisors (see below), whose sum is σ = 33550873920. Its totient is φ = 9937683840.

The previous prime is 21121101173. The next prime is 21121101247. The reversal of 21121101206 is 60210112112.

It is a super-2 number, since 2×21121101206² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 168611 + ... + 265841.

It is an arithmetic number, because the mean of its divisors is an integer number (2096929620).

Almost surely, 2^21121101206 is an apocalyptic number.

21121101206 is a deficient number, since it is larger than the sum of its proper divisors (12429772714).

21121101206 is a wasteful number, since it uses less digits than its factorization.

21121101206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103639.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 21121101206 its reverse (60210112112), we get a palindrome (81331213318).

The spelling of 21121101206 in words is "twenty-one billion, one hundred twenty-one million, one hundred one thousand, two hundred six".