21272099 has 2 divisors, whose sum is σ = 21272100. Its totient is φ = 21272098.

The previous prime is 21272047. The next prime is 21272101. The reversal of 21272099 is 99027212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21272099 - 2⁸ = 21271843 is a prime.

It is a Sophie Germain prime.

Together with 21272101, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21275099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10636049 + 10636050.

It is an arithmetic number, because the mean of its divisors is an integer number (10636050).

Almost surely, 2^21272099 is an apocalyptic number.

21272099 is a deficient number, since it is larger than the sum of its proper divisors (1).

21272099 is an equidigital number, since it uses as much as digits as its factorization.

21272099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 21272099 is about 4612.1685788791. The cubic root of 21272099 is about 277.0788959710.

The spelling of 21272099 in words is "twenty-one million, two hundred seventy-two thousand, ninety-nine".