21040235 has 8 divisors (see below), whose sum is σ = 25930896. Its totient is φ = 16377120.

The previous prime is 21040231. The next prime is 21040247. The reversal of 21040235 is 53204012.

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

It is not a de Polignac number, because 21040235 - 2² = 21040231 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21040231) 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, 56681 + ... + 57050.

It is an arithmetic number, because the mean of its divisors is an integer number (3241362).

Almost surely, 2^21040235 is an apocalyptic number.

21040235 is a deficient number, since it is larger than the sum of its proper divisors (4890661).

21040235 is a wasteful number, since it uses less digits than its factorization.

21040235 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113773.

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 21040235 is about 4586.9635926177. The cubic root of 21040235 is about 276.0685041396.

Adding to 21040235 its reverse (53204012), we get a palindrome (74244247).

The spelling of 21040235 in words is "twenty-one million, forty thousand, two hundred thirty-five".