21799263 has 4 divisors (see below), whose sum is σ = 29065688. Its totient is φ = 14532840.

The previous prime is 21799243. The next prime is 21799279. The reversal of 21799263 is 36299712.

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

It is not a de Polignac number, because 21799263 - 2⁶ = 21799199 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 (21799243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3633208 + ... + 3633213.

It is an arithmetic number, because the mean of its divisors is an integer number (7266422).

Almost surely, 2^21799263 is an apocalyptic number.

21799263 is a deficient number, since it is larger than the sum of its proper divisors (7266425).

21799263 is an equidigital number, since it uses as much as digits as its factorization.

21799263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7266424.

The product of its digits is 40824, while the sum is 39.

The square root of 21799263 is about 4668.9680872758. The cubic root of 21799263 is about 279.3490960372.

The spelling of 21799263 in words is "twenty-one million, seven hundred ninety-nine thousand, two hundred sixty-three".