21213130 has 32 divisors (see below), whose sum is σ = 40176000. Its totient is φ = 8048832.

The previous prime is 21213119. The next prime is 21213149. The reversal of 21213130 is 3131212.

It is a self number, because there is not a number n which added to its sum of digits gives 21213130.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33961 + ... + 34579.

It is an arithmetic number, because the mean of its divisors is an integer number (1255500).

Almost surely, 2^21213130 is an apocalyptic number.

21213130 is a deficient number, since it is larger than the sum of its proper divisors (18962870).

21213130 is a wasteful number, since it uses less digits than its factorization.

21213130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 798.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21213130 is about 4605.7713794760. The cubic root of 21213130 is about 276.8226262174.

Adding to 21213130 its reverse (3131212), we get a palindrome (24344342).

The spelling of 21213130 in words is "twenty-one million, two hundred thirteen thousand, one hundred thirty".