20391693 has 40 divisors (see below), whose sum is σ = 33612000. Its totient is φ = 10965024.

The previous prime is 20391677. The next prime is 20391713. The reversal of 20391693 is 39619302.

It is not a de Polignac number, because 20391693 - 2⁴ = 20391677 is a prime.

It is a super-2 number, since 2×20391693² = 831642286812498, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20395693) 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 39 ways as a sum of consecutive naturals, for example, 136783 + ... + 136931.

It is an arithmetic number, because the mean of its divisors is an integer number (840300).

Almost surely, 2^20391693 is an apocalyptic number.

It is an amenable number.

20391693 is a deficient number, since it is larger than the sum of its proper divisors (13220307).

20391693 is an equidigital number, since it uses as much as digits as its factorization.

20391693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 33.

The square root of 20391693 is about 4515.7162222620. The cubic root of 20391693 is about 273.2023483382.

The spelling of 20391693 in words is "twenty million, three hundred ninety-one thousand, six hundred ninety-three".