19897324445 has 18 divisors (see below), whose sum is σ = 24073316442. Its totient is φ = 15787908576.

The previous prime is 19897324439. The next prime is 19897324453. The reversal of 19897324445 is 54442379891.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 988599364 + 18908725081 = 31442^2 + 137509^2 .

It is not a de Polignac number, because 19897324445 - 2⁸ = 19897324189 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 62767427 + ... + 62767743.

It is an arithmetic number, because the mean of its divisors is an integer number (1337406469).

Almost surely, 2^19897324445 is an apocalyptic number.

It is an amenable number.

19897324445 is a deficient number, since it is larger than the sum of its proper divisors (4175991997).

19897324445 is an frugal number, since it uses more digits than its factorization.

19897324445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1037 (or 521 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 56.

The spelling of 19897324445 in words is "nineteen billion, eight hundred ninety-seven million, three hundred twenty-four thousand, four hundred forty-five".