19685821970 has 8 divisors (see below), whose sum is σ = 35434479564. Its totient is φ = 7874328784.

The previous prime is 19685821913. The next prime is 19685821999. The reversal of 19685821970 is 7912858691.

It can be written as a sum of positive squares in 2 ways, for example, as 18520760281 + 1165061689 = 136091^2 + 34133^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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 3 ways as a sum of consecutive naturals, for example, 984291089 + ... + 984291108.

Almost surely, 2^19685821970 is an apocalyptic number.

19685821970 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19685821970 is a deficient number, since it is larger than the sum of its proper divisors (15748657594).

19685821970 is a wasteful number, since it uses less digits than its factorization.

19685821970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1968582204.

The product of its (nonzero) digits is 2177280, while the sum is 56.

The spelling of 19685821970 in words is "nineteen billion, six hundred eighty-five million, eight hundred twenty-one thousand, nine hundred seventy".