20557707 has 4 divisors (see below), whose sum is σ = 27410280. Its totient is φ = 13705136.

The previous prime is 20557697. The next prime is 20557711. The reversal of 20557707 is 70775502.

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 20557707 - 2⁶ = 20557643 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20557507) 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, 3426282 + ... + 3426287.

It is an arithmetic number, because the mean of its divisors is an integer number (6852570).

Almost surely, 2^20557707 is an apocalyptic number.

20557707 is a deficient number, since it is larger than the sum of its proper divisors (6852573).

20557707 is an equidigital number, since it uses as much as digits as its factorization.

20557707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6852572.

The product of its (nonzero) digits is 17150, while the sum is 33.

The square root of 20557707 is about 4534.0607627159. The cubic root of 20557707 is about 273.9417488545.

The spelling of 20557707 in words is "twenty million, five hundred fifty-seven thousand, seven hundred seven".