20097919 has 4 divisors (see below), whose sum is σ = 20641144. Its totient is φ = 19554696.

The previous prime is 20097911. The next prime is 20097947. The reversal of 20097919 is 91979002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91979002 = 2 ⋅45989501.

It is a cyclic number.

It is not a de Polignac number, because 20097919 - 2³ = 20097911 is a prime.

It is a super-2 number, since 2×20097919² = 807852696261122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37), and also a Moran number because the ratio is a prime number: 543187 = 20097919 / (2 + 0 + 0 + 9 + 7 + 9 + 1 + 9).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20097911) 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, 271557 + ... + 271630.

It is an arithmetic number, because the mean of its divisors is an integer number (5160286).

Almost surely, 2^20097919 is an apocalyptic number.

20097919 is a deficient number, since it is larger than the sum of its proper divisors (543225).

20097919 is an equidigital number, since it uses as much as digits as its factorization.

20097919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 543224.

The product of its (nonzero) digits is 10206, while the sum is 37.

The square root of 20097919 is about 4483.0702648966. The cubic root of 20097919 is about 271.8840291008.

The spelling of 20097919 in words is "twenty million, ninety-seven thousand, nine hundred nineteen".