21975320 has 32 divisors (see below), whose sum is σ = 50500800. Its totient is φ = 8602368.

The previous prime is 21975313. The next prime is 21975323. The reversal of 21975320 is 2357912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21975323) 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 7 ways as a sum of consecutive naturals, for example, 3965 + ... + 7724.

It is an arithmetic number, because the mean of its divisors is an integer number (1578150).

Almost surely, 2^21975320 is an apocalyptic number.

21975320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21975320 is an abundant number, since it is smaller than the sum of its proper divisors (28525480).

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

21975320 is a wasteful number, since it uses less digits than its factorization.

21975320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11747 (or 11743 counting only the distinct ones).

The product of its (nonzero) digits is 3780, while the sum is 29.

The square root of 21975320 is about 4687.7841247225. The cubic root of 21975320 is about 280.0991145711.

The spelling of 21975320 in words is "twenty-one million, nine hundred seventy-five thousand, three hundred twenty".