21716099 has 4 divisors (see below), whose sum is σ = 22464960. Its totient is φ = 20967240.

The previous prime is 21716087. The next prime is 21716137. The reversal of 21716099 is 99061712.

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 21716099 - 2⁸ = 21715843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21716029) 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, 374387 + ... + 374444.

It is an arithmetic number, because the mean of its divisors is an integer number (5616240).

Almost surely, 2^21716099 is an apocalyptic number.

21716099 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

21716099 is a deficient number, since it is larger than the sum of its proper divisors (748861).

21716099 is an equidigital number, since it uses as much as digits as its factorization.

21716099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 748860.

The product of its (nonzero) digits is 6804, while the sum is 35.

The square root of 21716099 is about 4660.0535404650. The cubic root of 21716099 is about 278.9934052046.

The spelling of 21716099 in words is "twenty-one million, seven hundred sixteen thousand, ninety-nine".