1231535515 has 16 divisors (see below), whose sum is σ = 1689536448. Its totient is φ = 844194816.

The previous prime is 1231535479. The next prime is 1231535533. The reversal of 1231535515 is 5155351321.

It is a cyclic number.

It is not a de Polignac number, because 1231535515 - 2⁷ = 1231535387 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 181219 + ... + 187891.

It is an arithmetic number, because the mean of its divisors is an integer number (105596028).

Almost surely, 2^1231535515 is an apocalyptic number.

1231535515 is a deficient number, since it is larger than the sum of its proper divisors (458000933).

1231535515 is an equidigital number, since it uses as much as digits as its factorization.

1231535515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11958.

The product of its digits is 11250, while the sum is 31.

The square root of 1231535515 is about 35093.2403035114. The cubic root of 1231535515 is about 1071.8869417761.

Adding to 1231535515 its reverse (5155351321), we get a palindrome (6386886836).

The spelling of 1231535515 in words is "one billion, two hundred thirty-one million, five hundred thirty-five thousand, five hundred fifteen".