19393938816 has 64 divisors (see below), whose sum is σ = 58874465280. Its totient is φ = 5541124608.

The previous prime is 19393938797. The next prime is 19393938847. The reversal of 19393938816 is 61883939391.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×19393938816² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 19393938816.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3604816 + ... + 3610191.

It is an arithmetic number, because the mean of its divisors is an integer number (919913520).

Almost surely, 2^19393938816 is an apocalyptic number.

19393938816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

19393938816 is an abundant number, since it is smaller than the sum of its proper divisors (39480526464).

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

19393938816 is an equidigital number, since it uses as much as digits as its factorization.

19393938816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7215031 (or 7215019 counting only the distinct ones).

The product of its digits is 7558272, while the sum is 60.

The spelling of 19393938816 in words is "nineteen billion, three hundred ninety-three million, nine hundred thirty-eight thousand, eight hundred sixteen".