21312230 has 8 divisors (see below), whose sum is σ = 38362032. Its totient is φ = 8524888.

The previous prime is 21312229. The next prime is 21312233. The reversal of 21312230 is 3221312.

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 2×21312230² = 908422295145800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312233) 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, 1065602 + ... + 1065621.

It is an arithmetic number, because the mean of its divisors is an integer number (4795254).

Almost surely, 2^21312230 is an apocalyptic number.

21312230 is a deficient number, since it is larger than the sum of its proper divisors (17049802).

21312230 is a wasteful number, since it uses less digits than its factorization.

21312230 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2131230.

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

The square root of 21312230 is about 4616.5170854227. The cubic root of 21312230 is about 277.2530281054.

Adding to 21312230 its reverse (3221312), we get a palindrome (24533542).

The spelling of 21312230 in words is "twenty-one million, three hundred twelve thousand, two hundred thirty".