21672055 has 8 divisors (see below), whose sum is σ = 26076672. Its totient is φ = 17290848.

The previous prime is 21672041. The next prime is 21672061. The reversal of 21672055 is 55027612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21672055 - 2⁵ = 21672023 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 3744 + ... + 7573.

It is an arithmetic number, because the mean of its divisors is an integer number (3259584).

Almost surely, 2^21672055 is an apocalyptic number.

21672055 is a deficient number, since it is larger than the sum of its proper divisors (4404617).

21672055 is a wasteful number, since it uses less digits than its factorization.

21672055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11705.

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 21672055 is about 4655.3254451220. The cubic root of 21672055 is about 278.8046619394.

Adding to 21672055 its reverse (55027612), we get a palindrome (76699667).

The spelling of 21672055 in words is "twenty-one million, six hundred seventy-two thousand, fifty-five".