21109193 has 8 divisors (see below), whose sum is σ = 25173888. Its totient is φ = 17306784.

The previous prime is 21109181. The next prime is 21109201. The reversal of 21109193 is 39190112.

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 21109193 - 2⁴ = 21109177 is a prime.

It is a super-2 number, since 2×21109193² = 891196058222498, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21109103) 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, 65396 + ... + 65717.

It is an arithmetic number, because the mean of its divisors is an integer number (3146736).

Almost surely, 2^21109193 is an apocalyptic number.

21109193 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21109193 is a deficient number, since it is larger than the sum of its proper divisors (4064695).

21109193 is a wasteful number, since it uses less digits than its factorization.

21109193 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131143.

The product of its (nonzero) digits is 486, while the sum is 26.

The square root of 21109193 is about 4594.4741810135. The cubic root of 21109193 is about 276.3697740960.

The spelling of 21109193 in words is "twenty-one million, one hundred nine thousand, one hundred ninety-three".