1231177155 has 32 divisors (see below), whose sum is σ = 2123392320. Its totient is φ = 605552640.

The previous prime is 1231177153. The next prime is 1231177187. The reversal of 1231177155 is 5517711321.

It is not a de Polignac number, because 1231177155 - 2¹ = 1231177153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1231177153) 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 31 ways as a sum of consecutive naturals, for example, 272515 + ... + 276995.

It is an arithmetic number, because the mean of its divisors is an integer number (66356010).

Almost surely, 2^1231177155 is an apocalyptic number.

1231177155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1231177155 is a deficient number, since it is larger than the sum of its proper divisors (892215165).

1231177155 is a wasteful number, since it uses less digits than its factorization.

1231177155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5911.

The product of its digits is 7350, while the sum is 33.

The square root of 1231177155 is about 35088.1341054209. The cubic root of 1231177155 is about 1071.7829635408.

Adding to 1231177155 its reverse (5517711321), we get a palindrome (6748888476).

The spelling of 1231177155 in words is "one billion, two hundred thirty-one million, one hundred seventy-seven thousand, one hundred fifty-five".