20591959 has 4 divisors (see below), whose sum is σ = 20605816. Its totient is φ = 20578104.

The previous prime is 20591939. The next prime is 20591971. The reversal of 20591959 is 95919502.

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 20591959 - 2⁵ = 20591927 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 (20591939) 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, 4389 + ... + 7774.

It is an arithmetic number, because the mean of its divisors is an integer number (5151454).

Almost surely, 2^20591959 is an apocalyptic number.

20591959 is a deficient number, since it is larger than the sum of its proper divisors (13857).

20591959 is a wasteful number, since it uses less digits than its factorization.

20591959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13856.

The product of its (nonzero) digits is 36450, while the sum is 40.

The square root of 20591959 is about 4537.8363787162. The cubic root of 20591959 is about 274.0938061250.

The spelling of 20591959 in words is "twenty million, five hundred ninety-one thousand, nine hundred fifty-nine".