21672330 has 16 divisors (see below), whose sum is σ = 52013664.
Its totient is φ = 5779280.
The previous prime is 21672323. The next prime is 21672337. The reversal of 21672330 is 3327612.
Adding to 21672330 its reverse (3327612), we get a palindrome (24999942).
It is an interprime number because it is at equal distance from previous prime (21672323) and next prime (21672337).
It is a self number, because there is not a number n which added to its sum of digits gives 21672330.
It is not an unprimeable number, because it can be changed into a prime (21672337) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 361176 + ... + 361235.
It is an arithmetic number, because the mean of its divisors is an integer number (3250854).
Almost surely, 221672330 is an apocalyptic number.
21672330 is an abundant number, since it is smaller than the sum of its proper divisors (30341334).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
21672330 is a wasteful number, since it uses less digits than its factorization.
21672330 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 722421.
The product of its (nonzero) digits is 1512, while the sum is 24.
The square root of 21672330 is about 4655.3549810944.
The cubic root of 21672330 is about 278.8058411993.
The spelling of 21672330 in words is "twenty-one million, six hundred seventy-two thousand, three hundred thirty".