1155561012 has 24 divisors (see below), whose sum is σ = 2995899200. Its totient is φ = 385186968.

The previous prime is 1155560927. The next prime is 1155561013. The reversal of 1155561012 is 2101655511.

1155561012 is a `hidden beast` number, since 1 + 1 + 5 + 556 + 101 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1155561013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5349712 + ... + 5349927.

Almost surely, 2^1155561012 is an apocalyptic number.

1155561012 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1155561012 is an abundant number, since it is smaller than the sum of its proper divisors (1840338188).

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

1155561012 is a wasteful number, since it uses less digits than its factorization.

1155561012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10699652 (or 10699644 counting only the distinct ones).

The product of its (nonzero) digits is 1500, while the sum is 27.

The square root of 1155561012 is about 33993.5436811169. The cubic root of 1155561012 is about 1049.3755961060.

The spelling of 1155561012 in words is "one billion, one hundred fifty-five million, five hundred sixty-one thousand, twelve".