21320206 has 8 divisors (see below), whose sum is σ = 32105520. Its totient is φ = 10618368.

The previous prime is 21320203. The next prime is 21320209. The reversal of 21320206 is 60202312.

It is an interprime number because it is at equal distance from previous prime (21320203) and next prime (21320209).

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

It is a self number, because there is not a number n which added to its sum of digits gives 21320206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320203) 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, 20226 + ... + 21253.

It is an arithmetic number, because the mean of its divisors is an integer number (4013190).

Almost surely, 2^21320206 is an apocalyptic number.

21320206 is a deficient number, since it is larger than the sum of its proper divisors (10785314).

21320206 is a wasteful number, since it uses less digits than its factorization.

21320206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41738.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 21320206 is about 4617.3808593184. The cubic root of 21320206 is about 277.2876106643.

Adding to 21320206 its reverse (60202312), we get a palindrome (81522518).

The spelling of 21320206 in words is "twenty-one million, three hundred twenty thousand, two hundred six".