21672000 has 336 divisors, whose sum is σ = 90659712. Its totient is φ = 4838400.

The previous prime is 21671999. The next prime is 21672011. The reversal of 21672000 is 27612.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (336).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 503979 + ... + 504021.

Almost surely, 2^21672000 is an apocalyptic number.

21672000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21672000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45329856).

21672000 is an abundant number, since it is smaller than the sum of its proper divisors (68987712).

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

21672000 is a wasteful number, since it uses less digits than its factorization.

21672000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 21672000 is about 4655.3195379050. The cubic root of 21672000 is about 278.8044260862.

Adding to 21672000 its reverse (27612), we get a palindrome (21699612).

The spelling of 21672000 in words is "twenty-one million, six hundred seventy-two thousand".