21106393 has 12 divisors (see below), whose sum is σ = 26514880. Its totient is φ = 16445880.

The previous prime is 21106373. The next prime is 21106399. The reversal of 21106393 is 39360112.

It is not a de Polignac number, because 21106393 - 2⁵ = 21106361 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21106399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11613 + ... + 13306.

Almost surely, 2^21106393 is an apocalyptic number.

It is an amenable number.

21106393 is a deficient number, since it is larger than the sum of its proper divisors (5408487).

21106393 is a wasteful number, since it uses less digits than its factorization.

21106393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24948 (or 24937 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 21106393 is about 4594.1694570401. The cubic root of 21106393 is about 276.3575539923.

The spelling of 21106393 in words is "twenty-one million, one hundred six thousand, three hundred ninety-three".