21825450 has 120 divisors (see below), whose sum is σ = 64412172. Its totient is φ = 5460480.

The previous prime is 21825439. The next prime is 21825469. The reversal of 21825450 is 5452812.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 5349969 + 16475481 = 2313^2 + 4059^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 68692 + ... + 69008.

Almost surely, 2^21825450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21825450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32206086).

21825450 is an abundant number, since it is smaller than the sum of its proper divisors (42586722).

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

21825450 is a wasteful number, since it uses less digits than its factorization.

21825450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358 (or 344 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

The square root of 21825450 is about 4671.7716125684. The cubic root of 21825450 is about 279.4609100236.

The spelling of 21825450 in words is "twenty-one million, eight hundred twenty-five thousand, four hundred fifty".