1161555580 has 24 divisors (see below), whose sum is σ = 2440232928. Its totient is φ = 464438208.

The previous prime is 1161555553. The next prime is 1161555581. The reversal of 1161555580 is 855551611.

It is a happy number.

It is a super-3 number, since 3×1161555580³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1161555581) 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 7 ways as a sum of consecutive naturals, for example, 47682 + ... + 67798.

It is an arithmetic number, because the mean of its divisors is an integer number (101676372).

Almost surely, 2^1161555580 is an apocalyptic number.

1161555580 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1161555580 is an abundant number, since it is smaller than the sum of its proper divisors (1278677348).

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

1161555580 is a wasteful number, since it uses less digits than its factorization.

1161555580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23013 (or 23011 counting only the distinct ones).

The product of its (nonzero) digits is 30000, while the sum is 37.

The square root of 1161555580 is about 34081.6017816065. The cubic root of 1161555580 is about 1051.1870415010.

The spelling of 1161555580 in words is "one billion, one hundred sixty-one million, five hundred fifty-five thousand, five hundred eighty".