1581316211776 has 42 divisors (see below), whose sum is σ = 3650238545838. Its totient is φ = 677706946560.

The previous prime is 1581316211773. The next prime is 1581316211803. The reversal of 1581316211776 is 6771126131851.

It can be written as a sum of positive squares in only one way, i.e., 1349593358400 + 231722853376 = 1161720^2 + 481376^2 .

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (1581316211771) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 252119985 + ... + 252126256.

Almost surely, 2^{1581316211776} is an apocalyptic number.

1581316211776 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1581316211776 is an abundant number, since it is smaller than the sum of its proper divisors (2068922334062).

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

1581316211776 is an equidigital number, since it uses as much as digits as its factorization.

1581316211776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 504246267 (or 504246250 counting only the distinct ones).

The product of its digits is 423360, while the sum is 49.

The spelling of 1581316211776 in words is "one trillion, five hundred eighty-one billion, three hundred sixteen million, two hundred eleven thousand, seven hundred seventy-six".