19965176640 has 168 divisors, whose sum is σ = 68976666720. Its totient is φ = 5300419584.

The previous prime is 19965176629. The next prime is 19965176713. The reversal of 19965176640 is 4667156991.

It is a happy number.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 638491 + ... + 669029.

Almost surely, 2^19965176640 is an apocalyptic number.

19965176640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19965176640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34488333360).

19965176640 is an abundant number, since it is smaller than the sum of its proper divisors (49011490080).

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

19965176640 is a wasteful number, since it uses less digits than its factorization.

19965176640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30789 (or 30776 counting only the distinct ones).

The product of its (nonzero) digits is 2449440, while the sum is 54.

The spelling of 19965176640 in words is "nineteen billion, nine hundred sixty-five million, one hundred seventy-six thousand, six hundred forty".