1231045187 has 4 divisors (see below), whose sum is σ = 1233041016. Its totient is φ = 1229049360.

The previous prime is 1231045181. The next prime is 1231045201. The reversal of 1231045187 is 7815401321.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1231045187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231045181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 996989 + ... + 998222.

It is an arithmetic number, because the mean of its divisors is an integer number (308260254).

Almost surely, 2^1231045187 is an apocalyptic number.

1231045187 is a deficient number, since it is larger than the sum of its proper divisors (1995829).

1231045187 is an equidigital number, since it uses as much as digits as its factorization.

1231045187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1995828.

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 1231045187 is about 35086.2535332572. The cubic root of 1231045187 is about 1071.7446679125.

The spelling of 1231045187 in words is "one billion, two hundred thirty-one million, forty-five thousand, one hundred eighty-seven".