20681793 has 12 divisors (see below), whose sum is σ = 32589648. Its totient is φ = 12534360.

The previous prime is 20681777. The next prime is 20681813. The reversal of 20681793 is 39718602.

It is not a de Polignac number, because 20681793 - 2⁴ = 20681777 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20681723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 104355 + ... + 104552.

It is an arithmetic number, because the mean of its divisors is an integer number (2715804).

Almost surely, 2^20681793 is an apocalyptic number.

It is an amenable number.

20681793 is a deficient number, since it is larger than the sum of its proper divisors (11907855).

20681793 is a wasteful number, since it uses less digits than its factorization.

20681793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208924 (or 208921 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 20681793 is about 4547.7239362125. The cubic root of 20681793 is about 274.4918129880.

The spelling of 20681793 in words is "twenty million, six hundred eighty-one thousand, seven hundred ninety-three".