21266199 has 16 divisors (see below), whose sum is σ = 31584000. Its totient is φ = 14142168.

The previous prime is 21266173. The next prime is 21266207. The reversal of 21266199 is 99166212.

It is not a de Polignac number, because 21266199 - 2⁷ = 21266071 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21266129) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14502 + ... + 15900.

It is an arithmetic number, because the mean of its divisors is an integer number (1974000).

Almost surely, 2^21266199 is an apocalyptic number.

21266199 is a deficient number, since it is larger than the sum of its proper divisors (10317801).

21266199 is a wasteful number, since it uses less digits than its factorization.

21266199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1971 (or 1965 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 21266199 is about 4611.5289221689. The cubic root of 21266199 is about 277.0532768624.

The spelling of 21266199 in words is "twenty-one million, two hundred sixty-six thousand, one hundred ninety-nine".