21488385 has 8 divisors (see below), whose sum is σ = 34381440. Its totient is φ = 11460464.

The previous prime is 21488381. The next prime is 21488399. The reversal of 21488385 is 58388412.

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 21488385 - 2² = 21488381 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21488381) 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, 716265 + ... + 716294.

It is an arithmetic number, because the mean of its divisors is an integer number (4297680).

Almost surely, 2^21488385 is an apocalyptic number.

It is an amenable number.

21488385 is a deficient number, since it is larger than the sum of its proper divisors (12893055).

21488385 is a wasteful number, since it uses less digits than its factorization.

21488385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1432567.

The product of its digits is 61440, while the sum is 39.

The square root of 21488385 is about 4635.5566008841. The cubic root of 21488385 is about 278.0148060710.

The spelling of 21488385 in words is "twenty-one million, four hundred eighty-eight thousand, three hundred eighty-five".