21133899 has 16 divisors (see below), whose sum is σ = 31398400. Its totient is φ = 14049288.

The previous prime is 21133897. The next prime is 21133913. The reversal of 21133899 is 99833112.

It is not a de Polignac number, because 21133899 - 2¹ = 21133897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21133897) 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, 10962 + ... + 12744.

It is an arithmetic number, because the mean of its divisors is an integer number (1962400).

Almost surely, 2^21133899 is an apocalyptic number.

21133899 is a deficient number, since it is larger than the sum of its proper divisors (10264501).

21133899 is a wasteful number, since it uses less digits than its factorization.

21133899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2231 (or 2225 counting only the distinct ones).

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

The square root of 21133899 is about 4597.1620593579. The cubic root of 21133899 is about 276.4775522500.

The spelling of 21133899 in words is "twenty-one million, one hundred thirty-three thousand, eight hundred ninety-nine".