21070304 has 12 divisors (see below), whose sum is σ = 41482224. Its totient is φ = 10535136.

The previous prime is 21070267. The next prime is 21070307. The reversal of 21070304 is 40307012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21070307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 329192 + ... + 329255.

It is an arithmetic number, because the mean of its divisors is an integer number (3456852).

Almost surely, 2^21070304 is an apocalyptic number.

It is an amenable number.

21070304 is a deficient number, since it is larger than the sum of its proper divisors (20411920).

21070304 is an equidigital number, since it uses as much as digits as its factorization.

21070304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 658457 (or 658449 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 17.

The square root of 21070304 is about 4590.2400808672. The cubic root of 21070304 is about 276.1999531240.

Adding to 21070304 its reverse (40307012), we get a palindrome (61377316).

The spelling of 21070304 in words is "twenty-one million, seventy thousand, three hundred four".