20208993 has 32 divisors (see below), whose sum is σ = 32686080. Its totient is φ = 10860480.

The previous prime is 20208961. The next prime is 20209003. The reversal of 20208993 is 39980202.

It is not a de Polignac number, because 20208993 - 2⁵ = 20208961 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20200993) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23668 + ... + 24506.

It is an arithmetic number, because the mean of its divisors is an integer number (1021440).

Almost surely, 2^20208993 is an apocalyptic number.

It is an amenable number.

20208993 is a deficient number, since it is larger than the sum of its proper divisors (12477087).

20208993 is a wasteful number, since it uses less digits than its factorization.

20208993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 917.

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 20208993 is about 4495.4413576422. The cubic root of 20208993 is about 272.3839777665.

The spelling of 20208993 in words is "twenty million, two hundred eight thousand, nine hundred ninety-three".