1981886860 has 72 divisors (see below), whose sum is σ = 4465450080. Its totient is φ = 738656256.

The previous prime is 1981886857. The next prime is 1981886869. The reversal of 1981886860 is 686881891.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981886869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 593676 + ... + 597004.

It is an arithmetic number, because the mean of its divisors is an integer number (62020140).

Almost surely, 2^1981886860 is an apocalyptic number.

1981886860 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1981886860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2232725040).

1981886860 is an abundant number, since it is smaller than the sum of its proper divisors (2483563220).

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

1981886860 is a wasteful number, since it uses less digits than its factorization.

1981886860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3475 (or 3456 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 55.

The square root of 1981886860 is about 44518.3878863555. The cubic root of 1981886860 is about 1256.1059884256.

The spelling of 1981886860 in words is "one billion, nine hundred eighty-one million, eight hundred eighty-six thousand, eight hundred sixty".