1155661555 has 16 divisors (see below), whose sum is σ = 1458549504. Its totient is φ = 877818240.

The previous prime is 1155661541. The next prime is 1155661579. The reversal of 1155661555 is 5551665511.

It is not a de Polignac number, because 1155661555 - 2⁵ = 1155661523 is a prime.

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, 62124 + ... + 78553.

It is an arithmetic number, because the mean of its divisors is an integer number (91159344).

Almost surely, 2^1155661555 is an apocalyptic number.

1155661555 is a deficient number, since it is larger than the sum of its proper divisors (302887949).

1155661555 is a wasteful number, since it uses less digits than its factorization.

1155661555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140766.

The product of its digits is 112500, while the sum is 40.

The square root of 1155661555 is about 33995.0225033019. The cubic root of 1155661555 is about 1049.4060298981.

The spelling of 1155661555 in words is "one billion, one hundred fifty-five million, six hundred sixty-one thousand, five hundred fifty-five".