21180104 has 32 divisors (see below), whose sum is σ = 43770240. Its totient is φ = 9528000.

The previous prime is 21180101. The next prime is 21180139. The reversal of 21180104 is 40108112.

It is not an unprimeable number, because it can be changed into a prime (21180101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7697 + ... + 10079.

It is an arithmetic number, because the mean of its divisors is an integer number (1367820).

Almost surely, 2^21180104 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 21180104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21885120).

21180104 is an abundant number, since it is smaller than the sum of its proper divisors (22590136).

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

21180104 is a wasteful number, since it uses less digits than its factorization.

21180104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2501 (or 2497 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 21180104 is about 4602.1846985970. The cubic root of 21180104 is about 276.6788930259.

Adding to 21180104 its reverse (40108112), we get a palindrome (61288216).

The spelling of 21180104 in words is "twenty-one million, one hundred eighty thousand, one hundred four".