1161255561720 has 64 divisors (see below), whose sum is σ = 3484235308320. Its totient is φ = 309626494464.

The previous prime is 1161255561707. The next prime is 1161255561733. The reversal of 1161255561720 is 271655521611.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1161255561707) and next prime (1161255561733).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 250114 + ... + 1544366.

Almost surely, 2^{1161255561720} is an apocalyptic number.

1161255561720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1161255561720 is an abundant number, since it is smaller than the sum of its proper divisors (2322979746600).

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

1161255561720 is a wasteful number, since it uses less digits than its factorization.

1161255561720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1301744 (or 1301740 counting only the distinct ones).

The product of its (nonzero) digits is 126000, while the sum is 42.

The spelling of 1161255561720 in words is "one trillion, one hundred sixty-one billion, two hundred fifty-five million, five hundred sixty-one thousand, seven hundred twenty".