21306662 has 8 divisors (see below), whose sum is σ = 34418496. Its totient is φ = 9833832.

The previous prime is 21306617. The next prime is 21306707. The reversal of 21306662 is 26660312.

It is an interprime number because it is at equal distance from previous prime (21306617) and next prime (21306707).

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

It is a Harshad number since it is a multiple of its sum of digits (26), and also a Moran number because the ratio is a prime number: 819487 = 21306662 / (2 + 1 + 3 + 0 + 6 + 6 + 6 + 2).

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, 409718 + ... + 409769.

It is an arithmetic number, because the mean of its divisors is an integer number (4302312).

Almost surely, 2^21306662 is an apocalyptic number.

21306662 is a deficient number, since it is larger than the sum of its proper divisors (13111834).

21306662 is a wasteful number, since it uses less digits than its factorization.

21306662 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819502.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 21306662 is about 4615.9139939995. The cubic root of 21306662 is about 277.2288811044.

Adding to 21306662 its reverse (26660312), we get a palindrome (47966974).

The spelling of 21306662 in words is "twenty-one million, three hundred six thousand, six hundred sixty-two".