1231001155 has 8 divisors (see below), whose sum is σ = 1478001312. Its totient is φ = 984267648.

The previous prime is 1231001153. The next prime is 1231001159. The reversal of 1231001155 is 5511001321.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1231001155 - 2¹ = 1231001153 is a prime.

It is a super-2 number, since 2×1231001155² = 3030727687222668050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231001153) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56359 + ... + 75088.

It is an arithmetic number, because the mean of its divisors is an integer number (184750164).

Almost surely, 2^1231001155 is an apocalyptic number.

1231001155 is a deficient number, since it is larger than the sum of its proper divisors (247000157).

1231001155 is a wasteful number, since it uses less digits than its factorization.

1231001155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133325.

The product of its (nonzero) digits is 150, while the sum is 19.

The square root of 1231001155 is about 35085.6260454335. The cubic root of 1231001155 is about 1071.7318897128.

Adding to 1231001155 its reverse (5511001321), we get a palindrome (6742002476).

The spelling of 1231001155 in words is "one billion, two hundred thirty-one million, one thousand, one hundred fifty-five".