21672750 has 128 divisors (see below), whose sum is σ = 61461504. Its totient is φ = 5040000.

The previous prime is 21672733. The next prime is 21672769. The reversal of 21672750 is 5727612.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

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 63 ways as a sum of consecutive naturals, for example, 305215 + ... + 305285.

It is an arithmetic number, because the mean of its divisors is an integer number (480168).

Almost surely, 2^21672750 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21672750, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30730752).

21672750 is an abundant number, since it is smaller than the sum of its proper divisors (39788754).

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

21672750 is a wasteful number, since it uses less digits than its factorization.

21672750 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139 (or 129 counting only the distinct ones).

The product of its (nonzero) digits is 5880, while the sum is 30.

The square root of 21672750 is about 4655.4000902178. The cubic root of 21672750 is about 278.8076422316.

It can be divided in two parts, 21672 and 750, that added together give a palindrome (22422).

The spelling of 21672750 in words is "twenty-one million, six hundred seventy-two thousand, seven hundred fifty".