21117673 has 4 divisors (see below), whose sum is σ = 21162240. Its totient is φ = 21073108.

The previous prime is 21117671. The next prime is 21117697. The reversal of 21117673 is 37671112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21117673 - 2¹ = 21117671 is a prime.

It is a super-2 number, since 2×21117673² = 891912225869858, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21117671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21565 + ... + 22522.

It is an arithmetic number, because the mean of its divisors is an integer number (5290560).

Almost surely, 2^21117673 is an apocalyptic number.

It is an amenable number.

21117673 is a deficient number, since it is larger than the sum of its proper divisors (44567).

21117673 is an equidigital number, since it uses as much as digits as its factorization.

21117673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44566.

The product of its digits is 1764, while the sum is 28.

The square root of 21117673 is about 4595.3969360655. The cubic root of 21117673 is about 276.4067769621.

Adding to 21117673 its reverse (37671112), we get a palindrome (58788785).

The spelling of 21117673 in words is "twenty-one million, one hundred seventeen thousand, six hundred seventy-three".