20158791 has 16 divisors (see below), whose sum is σ = 28640640. Its totient is φ = 12575520.

The previous prime is 20158783. The next prime is 20158807. The reversal of 20158791 is 19785102.

It is not a de Polignac number, because 20158791 - 2³ = 20158783 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20158781) 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 15 ways as a sum of consecutive naturals, for example, 2601 + ... + 6861.

It is an arithmetic number, because the mean of its divisors is an integer number (1790040).

Almost surely, 2^20158791 is an apocalyptic number.

20158791 is a deficient number, since it is larger than the sum of its proper divisors (8481849).

20158791 is a wasteful number, since it uses less digits than its factorization.

20158791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4366.

The product of its (nonzero) digits is 5040, while the sum is 33.

The square root of 20158791 is about 4489.8542292596. The cubic root of 20158791 is about 272.1582439557.

The spelling of 20158791 in words is "twenty million, one hundred fifty-eight thousand, seven hundred ninety-one".