981819581819 has 4 divisors (see below), whose sum is σ = 982059580920. Its totient is φ = 981579582720.

The previous prime is 981819581783. The next prime is 981819581837. The reversal of 981819581819 is 918185918189.

981819581819 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 918185918189 = 20719 ⋅44316131.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-981819581819 is a prime.

It is a super-2 number, since 2×981819581819² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (981819583819) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 119993414 + ... + 120001595.

It is an arithmetic number, because the mean of its divisors is an integer number (245514895230).

Almost surely, 2^981819581819 is an apocalyptic number.

981819581819 is a deficient number, since it is larger than the sum of its proper divisors (239999101).

981819581819 is a wasteful number, since it uses less digits than its factorization.

981819581819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239999100.

The product of its digits is 14929920, while the sum is 68.

The spelling of 981819581819 in words is "nine hundred eighty-one billion, eight hundred nineteen million, five hundred eighty-one thousand, eight hundred nineteen".