19444598197 has 4 divisors (see below), whose sum is σ = 19970127916. Its totient is φ = 18919068480.

The previous prime is 19444598149. The next prime is 19444598231. The reversal of 19444598197 is 79189544491.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79189544491 = 1979 ⋅40014929.

It can be written as a sum of positive squares in 2 ways, for example, as 16292224881 + 3152373316 = 127641^2 + 56146^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19444598197 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 (19444598297) 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, 262764804 + ... + 262764877.

It is an arithmetic number, because the mean of its divisors is an integer number (4992531979).

Almost surely, 2^19444598197 is an apocalyptic number.

It is an amenable number.

19444598197 is a deficient number, since it is larger than the sum of its proper divisors (525529719).

19444598197 is an equidigital number, since it uses as much as digits as its factorization.

19444598197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525529718.

The product of its digits is 13063680, while the sum is 61.

The spelling of 19444598197 in words is "nineteen billion, four hundred forty-four million, five hundred ninety-eight thousand, one hundred ninety-seven".