20787713 has 4 divisors (see below), whose sum is σ = 21179988. Its totient is φ = 20395440.

The previous prime is 20787709. The next prime is 20787721. The reversal of 20787713 is 31778702.

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 6822544 + 13965169 = 2612^2 + 3737^2 .

It is a cyclic number.

It is not a de Polignac number, because 20787713 - 2² = 20787709 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20787743) 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, 196058 + ... + 196163.

It is an arithmetic number, because the mean of its divisors is an integer number (5294997).

Almost surely, 2^20787713 is an apocalyptic number.

It is an amenable number.

20787713 is a deficient number, since it is larger than the sum of its proper divisors (392275).

20787713 is an equidigital number, since it uses as much as digits as its factorization.

20787713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 392274.

The product of its (nonzero) digits is 16464, while the sum is 35.

The square root of 20787713 is about 4559.3544499194. The cubic root of 20787713 is about 274.9596105972.

The spelling of 20787713 in words is "twenty million, seven hundred eighty-seven thousand, seven hundred thirteen".