21638083 has 4 divisors (see below), whose sum is σ = 21648088. Its totient is φ = 21628080.

The previous prime is 21638069. The next prime is 21638117. The reversal of 21638083 is 38083612.

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 21638083 - 2⁹ = 21637571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21638033) 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, 258 + ... + 6583.

It is an arithmetic number, because the mean of its divisors is an integer number (5412022).

Almost surely, 2^21638083 is an apocalyptic number.

21638083 is a deficient number, since it is larger than the sum of its proper divisors (10005).

21638083 is an equidigital number, since it uses as much as digits as its factorization.

21638083 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10004.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 21638083 is about 4651.6752896134. The cubic root of 21638083 is about 278.6589057982.

The spelling of 21638083 in words is "twenty-one million, six hundred thirty-eight thousand, eighty-three".