21007199 has 2 divisors, whose sum is σ = 21007200. Its totient is φ = 21007198.

The previous prime is 21007183. The next prime is 21007201. The reversal of 21007199 is 99170012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21007199 - 2⁴ = 21007183 is a prime.

Together with 21007201, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21007139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10503599 + 10503600.

It is an arithmetic number, because the mean of its divisors is an integer number (10503600).

Almost surely, 2^21007199 is an apocalyptic number.

21007199 is a deficient number, since it is larger than the sum of its proper divisors (1).

21007199 is an equidigital number, since it uses as much as digits as its factorization.

21007199 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1134, while the sum is 29.

The square root of 21007199 is about 4583.3611029462. The cubic root of 21007199 is about 275.9239402191.

The spelling of 21007199 in words is "twenty-one million, seven thousand, one hundred ninety-nine".