1231565915 has 8 divisors (see below), whose sum is σ = 1479131280. Its totient is φ = 984417952.

The previous prime is 1231565903. The next prime is 1231565917. The reversal of 1231565915 is 5195651321.

It is a happy number.

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 1231565915 - 2¹⁴ = 1231549531 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1231565917) 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, 97820 + ... + 109689.

It is an arithmetic number, because the mean of its divisors is an integer number (184891410).

Almost surely, 2^1231565915 is an apocalyptic number.

1231565915 is a deficient number, since it is larger than the sum of its proper divisors (247565365).

1231565915 is a wasteful number, since it uses less digits than its factorization.

1231565915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208701.

The product of its digits is 40500, while the sum is 38.

The square root of 1231565915 is about 35093.6734326858. The cubic root of 1231565915 is about 1071.8957614148.

The spelling of 1231565915 in words is "one billion, two hundred thirty-one million, five hundred sixty-five thousand, nine hundred fifteen".