21630316 has 12 divisors (see below), whose sum is σ = 37885960. Its totient is φ = 10805760.

The previous prime is 21630289. The next prime is 21630337. The reversal of 21630316 is 61303612.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 6700 + ... + 9388.

Almost surely, 2^21630316 is an apocalyptic number.

It is an amenable number.

21630316 is a deficient number, since it is larger than the sum of its proper divisors (16255644).

21630316 is a wasteful number, since it uses less digits than its factorization.

21630316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4704 (or 4702 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 21630316 is about 4650.8403541726. The cubic root of 21630316 is about 278.6255602266.

Adding to 21630316 its reverse (61303612), we get a palindrome (82933928).

The spelling of 21630316 in words is "twenty-one million, six hundred thirty thousand, three hundred sixteen".