21816130 has 16 divisors (see below), whose sum is σ = 44879040. Its totient is φ = 7479792.

The previous prime is 21816107. The next prime is 21816163. The reversal of 21816130 is 3161812.

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 7 ways as a sum of consecutive naturals, for example, 155760 + ... + 155899.

It is an arithmetic number, because the mean of its divisors is an integer number (2804940).

Almost surely, 2^21816130 is an apocalyptic number.

21816130 is an abundant number, since it is smaller than the sum of its proper divisors (23062910).

21816130 is a wasteful number, since it uses less digits than its factorization.

21816130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311673.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 21816130 is about 4670.7740257906. The cubic root of 21816130 is about 279.4211254829.

Adding to 21816130 its reverse (3161812), we get a palindrome (24977942).

The spelling of 21816130 in words is "twenty-one million, eight hundred sixteen thousand, one hundred thirty".