19898756565 has 32 divisors (see below), whose sum is σ = 32254709760. Its totient is φ = 10474034496.

The previous prime is 19898756539. The next prime is 19898756569. The reversal of 19898756565 is 56565789891.

It is a happy number.

It is not a de Polignac number, because 19898756565 - 2¹⁴ = 19898740181 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19898756565.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19898756569) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1285864 + ... + 1301246.

It is an arithmetic number, because the mean of its divisors is an integer number (1007959680).

Almost surely, 2^19898756565 is an apocalyptic number.

19898756565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19898756565 is a deficient number, since it is larger than the sum of its proper divisors (12355953195).

19898756565 is a wasteful number, since it uses less digits than its factorization.

19898756565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16513.

The product of its digits is 163296000, while the sum is 69.

It can be divided in two parts, 198987 and 56565, that added together give a palindrome (255552).

The spelling of 19898756565 in words is "nineteen billion, eight hundred ninety-eight million, seven hundred fifty-six thousand, five hundred sixty-five".