20155993 has 16 divisors (see below), whose sum is σ = 24091200. Its totient is φ = 16620480.

The previous prime is 20155987. The next prime is 20156021. The reversal of 20155993 is 39955102.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20155993 - 2⁹ = 20155481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20155913) 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, 7243 + ... + 9631.

It is an arithmetic number, because the mean of its divisors is an integer number (1505700).

Almost surely, 2^20155993 is an apocalyptic number.

It is an amenable number.

20155993 is a deficient number, since it is larger than the sum of its proper divisors (3935207).

20155993 is a wasteful number, since it uses less digits than its factorization.

20155993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2472.

The product of its (nonzero) digits is 12150, while the sum is 34.

The square root of 20155993 is about 4489.5426270390. The cubic root of 20155993 is about 272.1456516992.

It can be divided in two parts, 2015 and 5993, that added together give a palindrome (8008).

The spelling of 20155993 in words is "twenty million, one hundred fifty-five thousand, nine hundred ninety-three".