21672167 has 16 divisors (see below), whose sum is σ = 24263712. Its totient is φ = 19192320.

The previous prime is 21672151. The next prime is 21672181. The reversal of 21672167 is 76127612.

It is a cyclic number.

It is not a de Polignac number, because 21672167 - 2⁴ = 21672151 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21672107) 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 15 ways as a sum of consecutive naturals, for example, 109913 + ... + 110109.

It is an arithmetic number, because the mean of its divisors is an integer number (1516482).

Almost surely, 2^21672167 is an apocalyptic number.

21672167 is a deficient number, since it is larger than the sum of its proper divisors (2591545).

21672167 is a wasteful number, since it uses less digits than its factorization.

21672167 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 418.

The product of its digits is 7056, while the sum is 32.

The square root of 21672167 is about 4655.3374743406. The cubic root of 21672167 is about 278.8051422210.

Adding to 21672167 its reverse (76127612), we get a palindrome (97799779).

Subtracting 21672167 from its reverse (76127612), we obtain a palindrome (54455445).

It can be divided in two parts, 2167 and 2167, that added together give a palindrome (4334).

The spelling of 21672167 in words is "twenty-one million, six hundred seventy-two thousand, one hundred sixty-seven".