21672007 has 8 divisors (see below), whose sum is σ = 25567232. Its totient is φ = 17976600.

The previous prime is 21671999. The next prime is 21672011. The reversal of 21672007 is 70027612.

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 21672007 - 2³ = 21671999 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 (21672097) 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, 49719 + ... + 50152.

It is an arithmetic number, because the mean of its divisors is an integer number (3195904).

Almost surely, 2^21672007 is an apocalyptic number.

21672007 is a deficient number, since it is larger than the sum of its proper divisors (3895225).

21672007 is an equidigital number, since it uses as much as digits as its factorization.

21672007 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99909.

The product of its (nonzero) digits is 1176, while the sum is 25.

The square root of 21672007 is about 4655.3202897330. The cubic root of 21672007 is about 278.8044561039.

Adding to 21672007 its reverse (70027612), we get a palindrome (91699619).

The spelling of 21672007 in words is "twenty-one million, six hundred seventy-two thousand, seven".