21308395 has 8 divisors (see below), whose sum is σ = 27074304. Its totient is φ = 16043904.

The previous prime is 21308393. The next prime is 21308431. The reversal of 21308395 is 59380312.

It is a happy number.

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 21308395 - 2¹ = 21308393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21308393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125259 + ... + 125428.

It is an arithmetic number, because the mean of its divisors is an integer number (3384288).

Almost surely, 2^21308395 is an apocalyptic number.

21308395 is a deficient number, since it is larger than the sum of its proper divisors (5765909).

21308395 is a wasteful number, since it uses less digits than its factorization.

21308395 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250709.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 21308395 is about 4616.1017103179. The cubic root of 21308395 is about 277.2363971359.

The spelling of 21308395 in words is "twenty-one million, three hundred eight thousand, three hundred ninety-five".