19838515665 has 16 divisors (see below), whose sum is σ = 31817030976. Its totient is φ = 10555406400.

The previous prime is 19838515649. The next prime is 19838515691. The reversal of 19838515665 is 56651583891.

It is a happy number.

It is not a de Polignac number, because 19838515665 - 2⁴ = 19838515649 is a prime.

It is a super-3 number, since 3×19838515665³ (a number of 32 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1564431 + ... + 1577060.

It is an arithmetic number, because the mean of its divisors is an integer number (1988564436).

Almost surely, 2^19838515665 is an apocalyptic number.

19838515665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19838515665 is a deficient number, since it is larger than the sum of its proper divisors (11978515311).

19838515665 is a wasteful number, since it uses less digits than its factorization.

19838515665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3141920.

The product of its digits is 7776000, while the sum is 57.

The spelling of 19838515665 in words is "nineteen billion, eight hundred thirty-eight million, five hundred fifteen thousand, six hundred sixty-five".