19685009898 has 12 divisors (see below), whose sum is σ = 42650854818. Its totient is φ = 6561669960.

The previous prime is 19685009863. The next prime is 19685009917. The reversal of 19685009898 is 89890058691.

It can be written as a sum of positive squares in only one way, i.e., 9979410609 + 9705599289 = 99897^2 + 98517^2 .

It is a super-2 number, since 2×19685009898² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 546805813 + ... + 546805848.

Almost surely, 2^19685009898 is an apocalyptic number.

19685009898 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

19685009898 is an abundant number, since it is smaller than the sum of its proper divisors (22965844920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19685009898 is a wasteful number, since it uses less digits than its factorization.

19685009898 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1093611669 (or 1093611666 counting only the distinct ones).

The product of its (nonzero) digits is 11197440, while the sum is 63.

The spelling of 19685009898 in words is "nineteen billion, six hundred eighty-five million, nine thousand, eight hundred ninety-eight".