1981327164 has 24 divisors (see below), whose sum is σ = 4686428880. Its totient is φ = 651394944.

The previous prime is 1981327147. The next prime is 1981327177. The reversal of 1981327164 is 4617231891.

It is a happy number.

1981327164 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×1981327164³ (a number of 29 digits) contains 333 as substring.

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, 1130019 + ... + 1131770.

It is an arithmetic number, because the mean of its divisors is an integer number (195267870).

Almost surely, 2^1981327164 is an apocalyptic number.

It is an amenable number.

1981327164 is an abundant number, since it is smaller than the sum of its proper divisors (2705101716).

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

1981327164 is a wasteful number, since it uses less digits than its factorization.

1981327164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2261869 (or 2261867 counting only the distinct ones).

The product of its digits is 72576, while the sum is 42.

The square root of 1981327164 is about 44512.1013208768. The cubic root of 1981327164 is about 1255.9877334935.

The spelling of 1981327164 in words is "one billion, nine hundred eighty-one million, three hundred twenty-seven thousand, one hundred sixty-four".