21050304 has 56 divisors (see below), whose sum is σ = 60764928. Its totient is φ = 6378240.

The previous prime is 21050303. The next prime is 21050311. The reversal of 21050304 is 40305012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21050303) 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, 2872 + ... + 7095.

It is an arithmetic number, because the mean of its divisors is an integer number (1085088).

Almost surely, 2^21050304 is an apocalyptic number.

21050304 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21050304 is an abundant number, since it is smaller than the sum of its proper divisors (39714624).

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

21050304 is a wasteful number, since it uses less digits than its factorization.

21050304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9993 (or 9983 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 21050304 is about 4588.0610283648. The cubic root of 21050304 is about 276.1125354993.

Adding to 21050304 its reverse (40305012), we get a palindrome (61355316).

The spelling of 21050304 in words is "twenty-one million, fifty thousand, three hundred four".