21011199 has 16 divisors (see below), whose sum is σ = 30741120. Its totient is φ = 12659360.

The previous prime is 21011191. The next prime is 21011231. The reversal of 21011199 is 99111012.

It is a cyclic number.

It is not a de Polignac number, because 21011199 - 2³ = 21011191 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011191) 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, 4129 + ... + 7685.

It is an arithmetic number, because the mean of its divisors is an integer number (1921320).

Almost surely, 2^21011199 is an apocalyptic number.

21011199 is a deficient number, since it is larger than the sum of its proper divisors (9729921).

21011199 is a wasteful number, since it uses less digits than its factorization.

21011199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3750.

The product of its (nonzero) digits is 162, while the sum is 24.

The square root of 21011199 is about 4583.7974431687. The cubic root of 21011199 is about 275.9414520844.

The spelling of 21011199 in words is "twenty-one million, eleven thousand, one hundred ninety-nine".