21347305 has 8 divisors (see below), whose sum is σ = 29276352. Its totient is φ = 14638128.

The previous prime is 21347297. The next prime is 21347309. The reversal of 21347305 is 50374312.

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

It is a cyclic number.

It is not a de Polignac number, because 21347305 - 2³ = 21347297 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21347305.

It is not an unprimeable number, because it can be changed into a prime (21347309) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 304927 + ... + 304996.

It is an arithmetic number, because the mean of its divisors is an integer number (3659544).

Almost surely, 2^21347305 is an apocalyptic number.

It is an amenable number.

21347305 is a deficient number, since it is larger than the sum of its proper divisors (7929047).

21347305 is an equidigital number, since it uses as much as digits as its factorization.

21347305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 609935.

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 21347305 is about 4620.3143832428. The cubic root of 21347305 is about 277.4050428561.

The spelling of 21347305 in words is "twenty-one million, three hundred forty-seven thousand, three hundred five".