21339545 has 8 divisors (see below), whose sum is σ = 25847424. Its totient is φ = 16911664.

The previous prime is 21339529. The next prime is 21339553. The reversal of 21339545 is 54593312.

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 21339545 - 2⁴ = 21339529 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 19409 + ... + 20478.

It is an arithmetic number, because the mean of its divisors is an integer number (3230928).

Almost surely, 2^21339545 is an apocalyptic number.

It is an amenable number.

21339545 is a deficient number, since it is larger than the sum of its proper divisors (4507879).

21339545 is a wasteful number, since it uses less digits than its factorization.

21339545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39999.

The product of its digits is 16200, while the sum is 32.

The square root of 21339545 is about 4619.4745372174. The cubic root of 21339545 is about 277.3714254350.

The spelling of 21339545 in words is "twenty-one million, three hundred thirty-nine thousand, five hundred forty-five".