1581969942720 has 560 divisors, whose sum is σ = 5836386600000. Its totient is φ = 406263029760.

The previous prime is 1581969942659. The next prime is 1581969942731. The reversal of 1581969942720 is 272499691851.

1581969942720 is a `hidden beast` number, since 1 + 581 + 9 + 6 + 9 + 9 + 4 + 27 + 20 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 316454781 + ... + 316459779.

Almost surely, 2^{1581969942720} is an apocalyptic number.

1581969942720 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 1581969942720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2918193300000).

1581969942720 is an abundant number, since it is smaller than the sum of its proper divisors (4254416657280).

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

1581969942720 is a wasteful number, since it uses less digits than its factorization.

1581969942720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5478 (or 5459 counting only the distinct ones).

The product of its (nonzero) digits is 19595520, while the sum is 63.

The spelling of 1581969942720 in words is "one trillion, five hundred eighty-one billion, nine hundred sixty-nine million, nine hundred forty-two thousand, seven hundred twenty".