19685532138 has 16 divisors (see below), whose sum is σ = 39845415456. Its totient is φ = 6482785520.

The previous prime is 19685532127. The next prime is 19685532157. The reversal of 19685532138 is 83123558691.

It is a happy number.

It is a super-3 number, since 3×19685532138³ (a number of 32 digits) contains 333 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 7 ways as a sum of consecutive naturals, for example, 19764093 + ... + 19765088.

It is an arithmetic number, because the mean of its divisors is an integer number (2490338466).

Almost surely, 2^19685532138 is an apocalyptic number.

19685532138 is an abundant number, since it is smaller than the sum of its proper divisors (20159883318).

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

19685532138 is a wasteful number, since it uses less digits than its factorization.

19685532138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39529269.

The product of its digits is 1555200, while the sum is 51.

The spelling of 19685532138 in words is "nineteen billion, six hundred eighty-five million, five hundred thirty-two thousand, one hundred thirty-eight".