21324975 has 48 divisors (see below), whose sum is σ = 40711680. Its totient is φ = 9648000.

The previous prime is 21324971. The next prime is 21324977. The reversal of 21324975 is 57942312.

It is not a de Polignac number, because 21324975 - 2² = 21324971 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21324971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 79141 + ... + 79409.

It is an arithmetic number, because the mean of its divisors is an integer number (848160).

Almost surely, 2^21324975 is an apocalyptic number.

21324975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21324975 is a deficient number, since it is larger than the sum of its proper divisors (19386705).

21324975 is a wasteful number, since it uses less digits than its factorization.

21324975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440 (or 435 counting only the distinct ones).

The product of its digits is 15120, while the sum is 33.

The square root of 21324975 is about 4617.8972487486. The cubic root of 21324975 is about 277.3082841047.

The spelling of 21324975 in words is "twenty-one million, three hundred twenty-four thousand, nine hundred seventy-five".