21735450 has 72 divisors (see below), whose sum is σ = 63719136. Its totient is φ = 5268000.

The previous prime is 21735431. The next prime is 21735451. The reversal of 21735450 is 5453712.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21735451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2755 + ... + 7145.

It is an arithmetic number, because the mean of its divisors is an integer number (884988).

Almost surely, 2^21735450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21735450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31859568).

21735450 is an abundant number, since it is smaller than the sum of its proper divisors (41983686).

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

21735450 is a wasteful number, since it uses less digits than its factorization.

21735450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4420 (or 4412 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 27.

The square root of 21735450 is about 4662.1293418351. The cubic root of 21735450 is about 279.0762500190.

The spelling of 21735450 in words is "twenty-one million, seven hundred thirty-five thousand, four hundred fifty".