21540335 has 16 divisors (see below), whose sum is σ = 26790912. Its totient is φ = 16615200.

The previous prime is 21540317. The next prime is 21540341. The reversal of 21540335 is 53304512.

It is not a de Polignac number, because 21540335 - 2⁶ = 21540271 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 21540335.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16040 + ... + 17330.

It is an arithmetic number, because the mean of its divisors is an integer number (1674432).

Almost surely, 2^21540335 is an apocalyptic number.

21540335 is a deficient number, since it is larger than the sum of its proper divisors (5250577).

21540335 is a wasteful number, since it uses less digits than its factorization.

21540335 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1414.

The product of its (nonzero) digits is 1800, while the sum is 23.

The square root of 21540335 is about 4641.1566446307. The cubic root of 21540335 is about 278.2386672535.

Adding to 21540335 its reverse (53304512), we get a palindrome (74844847).

The spelling of 21540335 in words is "twenty-one million, five hundred forty thousand, three hundred thirty-five".