21040304 has 10 divisors (see below), whose sum is σ = 40765620. Its totient is φ = 10520144.

The previous prime is 21040297. The next prime is 21040387. The reversal of 21040304 is 40304012.

It is a plaindrome in base 13.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 657494 + ... + 657525.

It is an arithmetic number, because the mean of its divisors is an integer number (4076562).

Almost surely, 2^21040304 is an apocalyptic number.

It is an amenable number.

21040304 is a deficient number, since it is larger than the sum of its proper divisors (19725316).

21040304 is a wasteful number, since it uses less digits than its factorization.

21040304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1315027 (or 1315021 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 21040304 is about 4586.9711139269. The cubic root of 21040304 is about 276.0688059219.

Adding to 21040304 its reverse (40304012), we get a palindrome (61344316).

The spelling of 21040304 in words is "twenty-one million, forty thousand, three hundred four".