20649271 has 4 divisors (see below), whose sum is σ = 21863952. Its totient is φ = 19434592.

The previous prime is 20649269. The next prime is 20649289. The reversal of 20649271 is 17294602.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20649271 - 2¹ = 20649269 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20649571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 607315 + ... + 607348.

It is an arithmetic number, because the mean of its divisors is an integer number (5465988).

Almost surely, 2^20649271 is an apocalyptic number.

20649271 is a deficient number, since it is larger than the sum of its proper divisors (1214681).

20649271 is a wasteful number, since it uses less digits than its factorization.

20649271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1214680.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 20649271 is about 4544.1468946327. The cubic root of 20649271 is about 274.3478585758.

The spelling of 20649271 in words is "twenty million, six hundred forty-nine thousand, two hundred seventy-one".