20193997 has 4 divisors (see below), whose sum is σ = 20221920. Its totient is φ = 20166076.

The previous prime is 20193991. The next prime is 20194037. The reversal of 20193997 is 79939102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20193997 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20193991) 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 3 ways as a sum of consecutive naturals, for example, 12847 + ... + 14332.

It is an arithmetic number, because the mean of its divisors is an integer number (5055480).

Almost surely, 2^20193997 is an apocalyptic number.

It is an amenable number.

20193997 is a deficient number, since it is larger than the sum of its proper divisors (27923).

20193997 is an equidigital number, since it uses as much as digits as its factorization.

20193997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27922.

The product of its (nonzero) digits is 30618, while the sum is 40.

The square root of 20193997 is about 4493.7731362409. The cubic root of 20193997 is about 272.3165872919.

The spelling of 20193997 in words is "twenty million, one hundred ninety-three thousand, nine hundred ninety-seven".