21672300 has 72 divisors (see below), whose sum is σ = 67540816. Its totient is φ = 5333760.

The previous prime is 21672271. The next prime is 21672319. The reversal of 21672300 is 327612.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1122 + ... + 6678.

Almost surely, 2^21672300 is an apocalyptic number.

21672300 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 21672300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33770408).

21672300 is an abundant number, since it is smaller than the sum of its proper divisors (45868516).

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

21672300 is a wasteful number, since it uses less digits than its factorization.

21672300 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5587 (or 5580 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 21672300 is about 4655.3517589974. The cubic root of 21672300 is about 278.8057125533.

Adding to 21672300 its reverse (327612), we get a palindrome (21999912).

The spelling of 21672300 in words is "twenty-one million, six hundred seventy-two thousand, three hundred".