21425385 has 8 divisors (see below), whose sum is σ = 34280640. Its totient is φ = 11426864.

The previous prime is 21425377. The next prime is 21425387. The reversal of 21425385 is 58352412.

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 21425385 - 2³ = 21425377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21425387) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 714165 + ... + 714194.

It is an arithmetic number, because the mean of its divisors is an integer number (4285080).

Almost surely, 2^21425385 is an apocalyptic number.

It is an amenable number.

21425385 is a deficient number, since it is larger than the sum of its proper divisors (12855255).

21425385 is a wasteful number, since it uses less digits than its factorization.

21425385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1428367.

The product of its digits is 9600, while the sum is 30.

The square root of 21425385 is about 4628.7563124451. The cubic root of 21425385 is about 277.7428439920.

Adding to 21425385 its reverse (58352412), we get a palindrome (79777797).

The spelling of 21425385 in words is "twenty-one million, four hundred twenty-five thousand, three hundred eighty-five".