20747717 has 4 divisors (see below), whose sum is σ = 20867820. Its totient is φ = 20627616.

The previous prime is 20747663. The next prime is 20747719. The reversal of 20747717 is 71774702.

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

It can be written as a sum of positive squares in 2 ways, for example, as 12630916 + 8116801 = 3554^2 + 2849^2 .

It is a cyclic number.

It is not a de Polignac number, because 20747717 - 2⁶ = 20747653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20747719) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 59792 + ... + 60137.

It is an arithmetic number, because the mean of its divisors is an integer number (5216955).

Almost surely, 2^20747717 is an apocalyptic number.

It is an amenable number.

20747717 is a deficient number, since it is larger than the sum of its proper divisors (120103).

20747717 is a wasteful number, since it uses less digits than its factorization.

20747717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120102.

The product of its (nonzero) digits is 19208, while the sum is 35.

The square root of 20747717 is about 4554.9661908734. The cubic root of 20747717 is about 274.7831546761.

The spelling of 20747717 in words is "twenty million, seven hundred forty-seven thousand, seven hundred seventeen".