1981367817320 has 64 divisors (see below), whose sum is σ = 4739678997120. Its totient is φ = 743784980224.

The previous prime is 1981367817283. The next prime is 1981367817323. The reversal of 1981367817320 is 237187631891.

It is a happy number.

It is a super-3 number, since 3×1981367817320³ (a number of 38 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (1981367817323) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20268794 + ... + 20366313.

It is an arithmetic number, because the mean of its divisors is an integer number (74057484330).

Almost surely, 2^{1981367817320} is an apocalyptic number.

1981367817320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1981367817320 is an abundant number, since it is smaller than the sum of its proper divisors (2758311179800).

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

1981367817320 is a wasteful number, since it uses less digits than its factorization.

1981367817320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40635194 (or 40635190 counting only the distinct ones).

The product of its (nonzero) digits is 3048192, while the sum is 56.

The spelling of 1981367817320 in words is "one trillion, nine hundred eighty-one billion, three hundred sixty-seven million, eight hundred seventeen thousand, three hundred twenty".