21673099 has 4 divisors (see below), whose sum is σ = 24769264. Its totient is φ = 18576936.

The previous prime is 21673073. The next prime is 21673103. The reversal of 21673099 is 99037612.

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

It is not a de Polignac number, because 21673099 - 2⁷ = 21672971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21673039) 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, 1548072 + ... + 1548085.

It is an arithmetic number, because the mean of its divisors is an integer number (6192316).

Almost surely, 2^21673099 is an apocalyptic number.

21673099 is a deficient number, since it is larger than the sum of its proper divisors (3096165).

21673099 is an equidigital number, since it uses as much as digits as its factorization.

21673099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3096164.

The product of its (nonzero) digits is 20412, while the sum is 37.

The square root of 21673099 is about 4655.4375734189. The cubic root of 21673099 is about 278.8091387860.

The spelling of 21673099 in words is "twenty-one million, six hundred seventy-three thousand, ninety-nine".