21675000 has 144 divisors (see below), whose sum is σ = 71948520. Its totient is φ = 5440000.

The previous prime is 21674999. The next prime is 21675013. The reversal of 21675000 is 57612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1274992 + ... + 1275008.

Almost surely, 2^21675000 is an apocalyptic number.

21675000 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 21675000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35974260).

21675000 is an abundant number, since it is smaller than the sum of its proper divisors (50273520).

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

21675000 is an equidigital number, since it uses as much as digits as its factorization.

21675000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68 (or 27 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 21675000 is about 4655.6417387939. The cubic root of 21675000 is about 278.8172902226.

The spelling of 21675000 in words is "twenty-one million, six hundred seventy-five thousand".