21133199 has 4 divisors (see below), whose sum is σ = 21861960. Its totient is φ = 20404440.

The previous prime is 21133153. The next prime is 21133213. The reversal of 21133199 is 99133112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21133199 is a prime.

It is a super-2 number, since 2×21133199² = 893224199947202, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 728731 = 21133199 / (2 + 1 + 1 + 3 + 3 + 1 + 9 + 9).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21133109) 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, 364337 + ... + 364394.

It is an arithmetic number, because the mean of its divisors is an integer number (5465490).

Almost surely, 2^21133199 is an apocalyptic number.

21133199 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

21133199 is a deficient number, since it is larger than the sum of its proper divisors (728761).

21133199 is an equidigital number, since it uses as much as digits as its factorization.

21133199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 728760.

The product of its digits is 1458, while the sum is 29.

The square root of 21133199 is about 4597.0859248006. The cubic root of 21133199 is about 276.4744997068.

The spelling of 21133199 in words is "twenty-one million, one hundred thirty-three thousand, one hundred ninety-nine".