19986873639 has 4 divisors (see below), whose sum is σ = 26649164856. Its totient is φ = 13324582424.

The previous prime is 19986873607. The next prime is 19986873659. The reversal of 19986873639 is 93637868991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93637868991 = 3 ⋅31212622997.

It is a cyclic number.

It is not a de Polignac number, because 19986873639 - 2⁵ = 19986873607 is a prime.

It is a super-2 number, since 2×19986873639² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19986873659) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3331145604 + ... + 3331145609.

It is an arithmetic number, because the mean of its divisors is an integer number (6662291214).

Almost surely, 2^19986873639 is an apocalyptic number.

19986873639 is a deficient number, since it is larger than the sum of its proper divisors (6662291217).

19986873639 is an equidigital number, since it uses as much as digits as its factorization.

19986873639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6662291216.

The product of its digits is 105815808, while the sum is 69.

The spelling of 19986873639 in words is "nineteen billion, nine hundred eighty-six million, eight hundred seventy-three thousand, six hundred thirty-nine".