21040271 has 8 divisors (see below), whose sum is σ = 25460640. Its totient is φ = 16973568.

The previous prime is 21040267. The next prime is 21040297. The reversal of 21040271 is 17204012.

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 21040271 - 2² = 21040267 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a congruent 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, 88286 + ... + 88523.

It is an arithmetic number, because the mean of its divisors is an integer number (3182580).

Almost surely, 2^21040271 is an apocalyptic number.

21040271 is a deficient number, since it is larger than the sum of its proper divisors (4420369).

21040271 is a wasteful number, since it uses less digits than its factorization.

21040271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176833.

The product of its (nonzero) digits is 112, while the sum is 17.

The square root of 21040271 is about 4586.9675167806. The cubic root of 21040271 is about 276.0686615913.

Adding to 21040271 its reverse (17204012), we get a palindrome (38244283).

The spelling of 21040271 in words is "twenty-one million, forty thousand, two hundred seventy-one".