21672174 has 8 divisors (see below), whose sum is σ = 43344360. Its totient is φ = 7224056.

The previous prime is 21672151. The next prime is 21672181. The reversal of 21672174 is 47127612.

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

21672174 is an admirable 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 3 ways as a sum of consecutive naturals, for example, 1806009 + ... + 1806020.

It is an arithmetic number, because the mean of its divisors is an integer number (5418045).

Almost surely, 2^21672174 is an apocalyptic number.

21672174 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21672174 is a wasteful number, since it uses less digits than its factorization.

21672174 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3612034.

The product of its digits is 4704, while the sum is 30.

The square root of 21672174 is about 4655.3382261657. The cubic root of 21672174 is about 278.8051722386.

Adding to 21672174 its reverse (47127612), we get a palindrome (68799786).

It can be divided in two parts, 216 and 72174, that added together give a triangular number (72390 = T₃₈₀).

The spelling of 21672174 in words is "twenty-one million, six hundred seventy-two thousand, one hundred seventy-four".