21321110 has 16 divisors (see below), whose sum is σ = 38905056. Its totient is φ = 8411328.

The previous prime is 21321101. The next prime is 21321121. The reversal of 21321110 is 1112312.

It is a junction number, because it is equal to n+sod(n) for n = 21321091 and 21321100.

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, 13874 + ... + 15333.

It is an arithmetic number, because the mean of its divisors is an integer number (2431566).

Almost surely, 2^21321110 is an apocalyptic number.

21321110 is a deficient number, since it is larger than the sum of its proper divisors (17583946).

21321110 is a wasteful number, since it uses less digits than its factorization.

21321110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29287.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 21321110 is about 4617.4787492743. The cubic root of 21321110 is about 277.2915297080.

Adding to 21321110 its reverse (1112312), we get a palindrome (22433422).

The spelling of 21321110 in words is "twenty-one million, three hundred twenty-one thousand, one hundred ten".