21213230 has 8 divisors (see below), whose sum is σ = 38183832. Its totient is φ = 8485288.

The previous prime is 21213193. The next prime is 21213251. The reversal of 21213230 is 3231212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21213230² = 900002254065800, which contains 22 as substring.

It is a congruent number.

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, 1060652 + ... + 1060671.

It is an arithmetic number, because the mean of its divisors is an integer number (4772979).

Almost surely, 2^21213230 is an apocalyptic number.

21213230 is a deficient number, since it is larger than the sum of its proper divisors (16970602).

21213230 is a wasteful number, since it uses less digits than its factorization.

21213230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2121330.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21213230 is about 4605.7822354080. The cubic root of 21213230 is about 276.8230612030.

Adding to 21213230 its reverse (3231212), we get a palindrome (24444442).

The spelling of 21213230 in words is "twenty-one million, two hundred thirteen thousand, two hundred thirty".