21191117 has 8 divisors (see below), whose sum is σ = 21513024. Its totient is φ = 20871648.

The previous prime is 21191111. The next prime is 21191123. The reversal of 21191117 is 71119112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21191111) and next prime (21191123).

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 21191117 - 2⁸ = 21190861 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21191092 and 21191101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21191111) 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, 23558 + ... + 24440.

It is an arithmetic number, because the mean of its divisors is an integer number (2689128).

Almost surely, 2^21191117 is an apocalyptic number.

It is an amenable number.

21191117 is a deficient number, since it is larger than the sum of its proper divisors (321907).

21191117 is a wasteful number, since it uses less digits than its factorization.

21191117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1219.

The product of its digits is 126, while the sum is 23.

The square root of 21191117 is about 4603.3810400618. The cubic root of 21191117 is about 276.7268395433.

The spelling of 21191117 in words is "twenty-one million, one hundred ninety-one thousand, one hundred seventeen".