21050604 has 42 divisors (see below), whose sum is σ = 55240220. Its totient is φ = 7015896.

The previous prime is 21050597. The next prime is 21050609. The reversal of 21050604 is 40605012.

It is a happy number.

21050604 is a `hidden beast` number, since 2 + 10 + 50 + 604 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21050609) 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 13 ways as a sum of consecutive naturals, for example, 694 + ... + 6525.

Almost surely, 2^21050604 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 21050604, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27620110).

21050604 is an abundant number, since it is smaller than the sum of its proper divisors (34189616).

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

21050604 is an equidigital number, since it uses as much as digits as its factorization.

21050604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7241 (or 7224 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21050604 is about 4588.0937217978. The cubic root of 21050604 is about 276.1138471726.

Adding to 21050604 its reverse (40605012), we get a palindrome (61655616).

The spelling of 21050604 in words is "twenty-one million, fifty thousand, six hundred four".