21975330 has 96 divisors (see below), whose sum is σ = 59701824. Its totient is φ = 5144832.

The previous prime is 21975323. The next prime is 21975347. The reversal of 21975330 is 3357912.

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 (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 327957 + ... + 328023.

It is an arithmetic number, because the mean of its divisors is an integer number (621894).

Almost surely, 2^21975330 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21975330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29850912).

21975330 is an abundant number, since it is smaller than the sum of its proper divisors (37726494).

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

21975330 is a wasteful number, since it uses less digits than its factorization.

21975330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 5670, while the sum is 30.

The square root of 21975330 is about 4687.7851913244. The cubic root of 21975330 is about 280.0991570580.

The spelling of 21975330 in words is "twenty-one million, nine hundred seventy-five thousand, three hundred thirty".