21673111 has 4 divisors (see below), whose sum is σ = 21695400. Its totient is φ = 21650824.

The previous prime is 21673103. The next prime is 21673139. The reversal of 21673111 is 11137612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21673111 - 2³ = 21673103 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21673511) 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 3 ways as a sum of consecutive naturals, for example, 9616 + ... + 11653.

It is an arithmetic number, because the mean of its divisors is an integer number (5423850).

Almost surely, 2^21673111 is an apocalyptic number.

21673111 is a deficient number, since it is larger than the sum of its proper divisors (22289).

21673111 is a wasteful number, since it uses less digits than its factorization.

21673111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22288.

The product of its digits is 252, while the sum is 22.

The square root of 21673111 is about 4655.4388622342. The cubic root of 21673111 is about 278.8091902431.

The spelling of 21673111 in words is "twenty-one million, six hundred seventy-three thousand, one hundred eleven".