1987581153856 has 21 divisors (see below), whose sum is σ = 3944128733139. Its totient is φ = 993784937664.

The previous prime is 1987581153851. The next prime is 1987581153931. The reversal of 1987581153856 is 6583511857891.

The square root of 1987581153856 is 1409816.

It is a perfect power (a square), and thus also a powerful number.

It is a super-3 number, since 3×1987581153856³ (a number of 38 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1987581153791 and 1987581153800.

It is not an unprimeable number, because it can be changed into a prime (1987581153851) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 11190415 + ... + 11366641.

It is an arithmetic number, because the mean of its divisors is an integer number (187815653959).

Almost surely, 2^{1987581153856} is an apocalyptic number.

1987581153856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

1987581153856 is the 1409816-th square number.

It is an amenable number.

1987581153856 is a deficient number, since it is larger than the sum of its proper divisors (1956547579283).

1987581153856 is an frugal number, since it uses more digits than its factorization.

1987581153856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352466 (or 176229 counting only the distinct ones).

The product of its digits is 72576000, while the sum is 67.

The spelling of 1987581153856 in words is "one trillion, nine hundred eighty-seven billion, five hundred eighty-one million, one hundred fifty-three thousand, eight hundred fifty-six".