21312104 has 32 divisors (see below), whose sum is σ = 43848000. Its totient is φ = 9630720.

The previous prime is 21312079. The next prime is 21312107. The reversal of 21312104 is 40121312.

It is not an unprimeable number, because it can be changed into a prime (21312107) 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, 16904 + ... + 18120.

It is an arithmetic number, because the mean of its divisors is an integer number (1370250).

Almost surely, 2^21312104 is an apocalyptic number.

It is an amenable number.

21312104 is an abundant number, since it is smaller than the sum of its proper divisors (22535896).

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

21312104 is a wasteful number, since it uses less digits than its factorization.

21312104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1433 (or 1429 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 21312104 is about 4616.5034387510. The cubic root of 21312104 is about 277.2524817220.

Adding to 21312104 its reverse (40121312), we get a palindrome (61433416).

The spelling of 21312104 in words is "twenty-one million, three hundred twelve thousand, one hundred four".