21004612 has 12 divisors (see below), whose sum is σ = 38356416. Its totient is φ = 10045640.

The previous prime is 21004609. The next prime is 21004619. The reversal of 21004612 is 21640012.

It is not an unprimeable number, because it can be changed into a prime (21004619) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114064 + ... + 114247.

It is an arithmetic number, because the mean of its divisors is an integer number (3196368).

Almost surely, 2^21004612 is an apocalyptic number.

It is an amenable number.

21004612 is a deficient number, since it is larger than the sum of its proper divisors (17351804).

21004612 is a wasteful number, since it uses less digits than its factorization.

21004612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228338 (or 228336 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 21004612 is about 4583.0788777851. The cubic root of 21004612 is about 275.9126132364.

Adding to 21004612 its reverse (21640012), we get a palindrome (42644624).

The spelling of 21004612 in words is "twenty-one million, four thousand, six hundred twelve".