1981155671040 has 1408 divisors, whose sum is σ = 8129371299840. Its totient is φ = 400683958272.

The previous prime is 1981155671029. The next prime is 1981155671041. The reversal of 1981155671040 is 401765511891.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981155671041) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 3481819876 + ... + 3481820444.

Almost surely, 2^{1981155671040} is an apocalyptic number.

1981155671040 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 1981155671040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4064685649920).

1981155671040 is an abundant number, since it is smaller than the sum of its proper divisors (6148215628800).

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

1981155671040 is a wasteful number, since it uses less digits than its factorization.

1981155671040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 717 (or 699 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 48.

The spelling of 1981155671040 in words is "one trillion, nine hundred eighty-one billion, one hundred fifty-five million, six hundred seventy-one thousand, forty".