1231531151 has 4 divisors (see below), whose sum is σ = 1296348600. Its totient is φ = 1166713704.

The previous prime is 1231531129. The next prime is 1231531157. The reversal of 1231531151 is 1511351321.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1231531151 - 2³⁰ = 157789327 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231531157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32408696 + ... + 32408733.

It is an arithmetic number, because the mean of its divisors is an integer number (324087150).

Almost surely, 2^1231531151 is an apocalyptic number.

1231531151 is a deficient number, since it is larger than the sum of its proper divisors (64817449).

1231531151 is an equidigital number, since it uses as much as digits as its factorization.

1231531151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64817448.

The product of its digits is 450, while the sum is 23.

The square root of 1231531151 is about 35093.1781262399. The cubic root of 1231531151 is about 1071.8856756818.

Adding to 1231531151 its reverse (1511351321), we get a palindrome (2742882472).

The spelling of 1231531151 in words is "one billion, two hundred thirty-one million, five hundred thirty-one thousand, one hundred fifty-one".