21164104 has 32 divisors (see below), whose sum is σ = 42993720. Its totient is φ = 9709056.

The previous prime is 21164093. The next prime is 21164107. The reversal of 21164104 is 40146112.

It can be written as a sum of positive squares in 4 ways, for example, as 21141604 + 22500 = 4598^2 + 150^2 .

It is not an unprimeable number, because it can be changed into a prime (21164107) 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, 19972 + ... + 21004.

Almost surely, 2^21164104 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21164104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21496860).

21164104 is an abundant number, since it is smaller than the sum of its proper divisors (21829616).

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

21164104 is a wasteful number, since it uses less digits than its factorization.

21164104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1249 (or 1245 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 21164104 is about 4600.4460653289. The cubic root of 21164104 is about 276.6092053373.

The spelling of 21164104 in words is "twenty-one million, one hundred sixty-four thousand, one hundred four".