21732385 has 8 divisors (see below), whose sum is σ = 26571240. Its totient is φ = 17057664.

The previous prime is 21732383. The next prime is 21732413. The reversal of 21732385 is 58323712.

It can be written as a sum of positive squares in 4 ways, for example, as 9684544 + 12047841 = 3112^2 + 3471^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21732385 - 2¹ = 21732383 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21732383) 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, 40740 + ... + 41269.

It is an arithmetic number, because the mean of its divisors is an integer number (3321405).

Almost surely, 2^21732385 is an apocalyptic number.

It is an amenable number.

21732385 is a deficient number, since it is larger than the sum of its proper divisors (4838855).

21732385 is an equidigital number, since it uses as much as digits as its factorization.

21732385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82067.

The product of its digits is 10080, while the sum is 31.

The square root of 21732385 is about 4661.8006177871. The cubic root of 21732385 is about 279.0631315280.

The spelling of 21732385 in words is "twenty-one million, seven hundred thirty-two thousand, three hundred eighty-five".