21113345 has 16 divisors (see below), whose sum is σ = 28164672. Its totient is φ = 15063360.

The previous prime is 21113329. The next prime is 21113357. The reversal of 21113345 is 54331112.

It is not a de Polignac number, because 21113345 - 2⁴ = 21113329 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 (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 707 + ... + 6536.

It is an arithmetic number, because the mean of its divisors is an integer number (1760292).

Almost surely, 2^21113345 is an apocalyptic number.

It is an amenable number.

21113345 is a deficient number, since it is larger than the sum of its proper divisors (7051327).

21113345 is a wasteful number, since it uses less digits than its factorization.

21113345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7312.

The product of its digits is 360, while the sum is 20.

The square root of 21113345 is about 4594.9260059331. The cubic root of 21113345 is about 276.3878927750.

Adding to 21113345 its reverse (54331112), we get a palindrome (75444457).

The spelling of 21113345 in words is "twenty-one million, one hundred thirteen thousand, three hundred forty-five".