19857355597 has 6 divisors (see below), whose sum is σ = 21094146218. Its totient is φ = 18689275584.

The previous prime is 19857355517. The next prime is 19857355603. The reversal of 19857355597 is 79555375891.

It can be written as a sum of positive squares in 3 ways, for example, as 10552631076 + 9304724521 = 102726^2 + 96461^2 .

It is not a de Polignac number, because 19857355597 - 2¹⁵ = 19857322829 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 (19857355517) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 34354998 + ... + 34355575.

Almost surely, 2^19857355597 is an apocalyptic number.

19857355597 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

19857355597 is a deficient number, since it is larger than the sum of its proper divisors (1236790621).

19857355597 is an equidigital number, since it uses as much as digits as its factorization.

19857355597 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68710607 (or 68710590 counting only the distinct ones).

The product of its digits is 59535000, while the sum is 64.

The spelling of 19857355597 in words is "nineteen billion, eight hundred fifty-seven million, three hundred fifty-five thousand, five hundred ninety-seven".