21672299 has 4 divisors (see below), whose sum is σ = 23642520. Its totient is φ = 19702080.

The previous prime is 21672271. The next prime is 21672319. The reversal of 21672299 is 99227612.

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

It is a cyclic number.

It is not a de Polignac number, because 21672299 - 2¹² = 21668203 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21672239) 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, 985094 + ... + 985115.

It is an arithmetic number, because the mean of its divisors is an integer number (5910630).

Almost surely, 2^21672299 is an apocalyptic number.

21672299 is a deficient number, since it is larger than the sum of its proper divisors (1970221).

21672299 is a wasteful number, since it uses less digits than its factorization.

21672299 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1970220.

The product of its digits is 27216, while the sum is 38.

The square root of 21672299 is about 4655.3516515941. The cubic root of 21672299 is about 278.8057082651.

The spelling of 21672299 in words is "twenty-one million, six hundred seventy-two thousand, two hundred ninety-nine".