21132799 has 4 divisors (see below), whose sum is σ = 21142440. Its totient is φ = 21123160.

The previous prime is 21132773. The next prime is 21132817. The reversal of 21132799 is 99723112.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21132799 - 2⁵ = 21132767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21132719) 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, 237 + ... + 6505.

It is an arithmetic number, because the mean of its divisors is an integer number (5285610).

Almost surely, 2^21132799 is an apocalyptic number.

21132799 is a deficient number, since it is larger than the sum of its proper divisors (9641).

21132799 is an equidigital number, since it uses as much as digits as its factorization.

21132799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9640.

The product of its digits is 6804, while the sum is 34.

The square root of 21132799 is about 4597.0424187732. The cubic root of 21132799 is about 276.4727553661.

The spelling of 21132799 in words is "twenty-one million, one hundred thirty-two thousand, seven hundred ninety-nine".