19816500066 has 32 divisors (see below), whose sum is σ = 43245232128. Its totient is φ = 6003717840.

The previous prime is 19816500043. The next prime is 19816500089. The reversal of 19816500066 is 66000561891.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (19816500043) and next prime (19816500089).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 306231 + ... + 365253.

It is an arithmetic number, because the mean of its divisors is an integer number (1351413504).

Almost surely, 2^19816500066 is an apocalyptic number.

19816500066 is an abundant number, since it is smaller than the sum of its proper divisors (23428732062).

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

19816500066 is a wasteful number, since it uses less digits than its factorization.

19816500066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64126.

The product of its (nonzero) digits is 77760, while the sum is 42.

The spelling of 19816500066 in words is "nineteen billion, eight hundred sixteen million, five hundred thousand, sixty-six".