19961670500 has 72 divisors (see below), whose sum is σ = 44365821864. Its totient is φ = 7844064000.

The previous prime is 19961670481. The next prime is 19961670523. The reversal of 19961670500 is 507616991.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 11628171556 + 8333498944 = 107834^2 + 91288^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24674096 + ... + 24674904.

Almost surely, 2^19961670500 is an apocalyptic number.

19961670500 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 19961670500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22182910932).

19961670500 is an abundant number, since it is smaller than the sum of its proper divisors (24404151364).

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

19961670500 is an frugal number, since it uses more digits than its factorization.

19961670500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1698 (or 877 counting only the distinct ones).

The product of its (nonzero) digits is 102060, while the sum is 44.

The spelling of 19961670500 in words is "nineteen billion, nine hundred sixty-one million, six hundred seventy thousand, five hundred".