19997927 has 4 divisors (see below), whose sum is σ = 20069376. Its totient is φ = 19926480.

The previous prime is 19997911. The next prime is 19997953. The reversal of 19997927 is 72979991.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19997927 - 2⁴ = 19997911 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19997027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35303 + ... + 35864.

It is an arithmetic number, because the mean of its divisors is an integer number (5017344).

Almost surely, 2^19997927 is an apocalyptic number.

19997927 is a deficient number, since it is larger than the sum of its proper divisors (71449).

19997927 is an equidigital number, since it uses as much as digits as its factorization.

19997927 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71448.

The product of its digits is 642978, while the sum is 53.

The square root of 19997927 is about 4471.9041805477. The cubic root of 19997927 is about 271.4323830226.

The spelling of 19997927 in words is "nineteen million, nine hundred ninety-seven thousand, nine hundred twenty-seven".