21131106 has 16 divisors (see below), whose sum is σ = 43161984. Its totient is φ = 6893744.

The previous prime is 21131087. The next prime is 21131137. The reversal of 21131106 is 60113112.

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, 37185 + ... + 37748.

It is an arithmetic number, because the mean of its divisors is an integer number (2697624).

Almost surely, 2^21131106 is an apocalyptic number.

21131106 is an abundant number, since it is smaller than the sum of its proper divisors (22030878).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21131106 is a wasteful number, since it uses less digits than its factorization.

21131106 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74985.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 21131106 is about 4596.8582749526. The cubic root of 21131106 is about 276.4653722003.

Adding to 21131106 its reverse (60113112), we get a palindrome (81244218).

The spelling of 21131106 in words is "twenty-one million, one hundred thirty-one thousand, one hundred six".