21004410 has 64 divisors (see below), whose sum is σ = 59616000. Its totient is φ = 4634112.

The previous prime is 21004387. The next prime is 21004447. The reversal of 21004410 is 1440012.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4366 + ... + 7814.

It is an arithmetic number, because the mean of its divisors is an integer number (931500).

Almost surely, 2^21004410 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21004410, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29808000).

21004410 is an abundant number, since it is smaller than the sum of its proper divisors (38611590).

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

21004410 is a wasteful number, since it uses less digits than its factorization.

21004410 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3495.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 21004410 is about 4583.0568401450. The cubic root of 21004410 is about 275.9117287556.

Adding to 21004410 its reverse (1440012), we get a palindrome (22444422).

It can be divided in two parts, 2100 and 4410, that multiplied together give a cube (9261000 = 210³).

The spelling of 21004410 in words is "twenty-one million, four thousand, four hundred ten".