21142385 has 8 divisors (see below), whose sum is σ = 27677376. Its totient is φ = 15376240.

The previous prime is 21142379. The next prime is 21142393. The reversal of 21142385 is 58324112.

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

It is not a de Polignac number, because 21142385 - 2¹⁰ = 21141361 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 192149 + ... + 192258.

It is an arithmetic number, because the mean of its divisors is an integer number (3459672).

Almost surely, 2^21142385 is an apocalyptic number.

It is an amenable number.

21142385 is a deficient number, since it is larger than the sum of its proper divisors (6534991).

21142385 is a wasteful number, since it uses less digits than its factorization.

21142385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384423.

The product of its digits is 1920, while the sum is 26.

The square root of 21142385 is about 4598.0849274453. The cubic root of 21142385 is about 276.5145524356.

Adding to 21142385 its reverse (58324112), we get a palindrome (79466497).

The spelling of 21142385 in words is "twenty-one million, one hundred forty-two thousand, three hundred eighty-five".