21340306 has 24 divisors (see below), whose sum is σ = 36497520. Its totient is φ = 9328176.

The previous prime is 21340289. The next prime is 21340313. The reversal of 21340306 is 60304312.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4761 + ... + 8083.

It is an arithmetic number, because the mean of its divisors is an integer number (1520730).

Almost surely, 2^21340306 is an apocalyptic number.

21340306 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21340306 is a deficient number, since it is larger than the sum of its proper divisors (15157214).

21340306 is a wasteful number, since it uses less digits than its factorization.

21340306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3370 (or 3357 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 19.

The square root of 21340306 is about 4619.5569051588. The cubic root of 21340306 is about 277.3747225554.

Adding to 21340306 its reverse (60304312), we get a palindrome (81644618).

The spelling of 21340306 in words is "twenty-one million, three hundred forty thousand, three hundred six".