1161917281812 has 144 divisors (see below), whose sum is σ = 3374187996480. Its totient is φ = 309347942400.

The previous prime is 1161917281799. The next prime is 1161917281813. The reversal of 1161917281812 is 2181827191611.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1161917281813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 170989 + ... + 1533972.

Almost surely, 2^{1161917281812} is an apocalyptic number.

1161917281812 is a gapful number since it is divisible by the number (12) 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 1161917281812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1687093998240).

1161917281812 is an abundant number, since it is smaller than the sum of its proper divisors (2212270714668).

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

1161917281812 is a wasteful number, since it uses less digits than its factorization.

1161917281812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1705062 (or 1705053 counting only the distinct ones).

The product of its digits is 96768, while the sum is 48.

The spelling of 1161917281812 in words is "one trillion, one hundred sixty-one billion, nine hundred seventeen million, two hundred eighty-one thousand, eight hundred twelve".