1986771731880 has 256 divisors, whose sum is σ = 6450975820800. Its totient is φ = 486604984320.

The previous prime is 1986771731849. The next prime is 1986771731897. The reversal of 1986771731880 is 881371776891.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 382289442 + ... + 382294638.

It is an arithmetic number, because the mean of its divisors is an integer number (25199124300).

Almost surely, 2^{1986771731880} is an apocalyptic number.

1986771731880 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 1986771731880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3225487910400).

1986771731880 is an abundant number, since it is smaller than the sum of its proper divisors (4464204088920).

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

1986771731880 is a wasteful number, since it uses less digits than its factorization.

1986771731880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6404 (or 6400 counting only the distinct ones).

The product of its (nonzero) digits is 28449792, while the sum is 66.

The spelling of 1986771731880 in words is "one trillion, nine hundred eighty-six billion, seven hundred seventy-one million, seven hundred thirty-one thousand, eight hundred eighty".