1231155605 has 8 divisors (see below), whose sum is σ = 1479358464. Its totient is φ = 983610000.

The previous prime is 1231155593. The next prime is 1231155617. The reversal of 1231155605 is 5065511321.

It is an interprime number because it is at equal distance from previous prime (1231155593) and next prime (1231155617).

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

It is not a de Polignac number, because 1231155605 - 2¹⁰ = 1231154581 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 160181 + ... + 167690.

It is an arithmetic number, because the mean of its divisors is an integer number (184919808).

Almost surely, 2^1231155605 is an apocalyptic number.

It is an amenable number.

1231155605 is a deficient number, since it is larger than the sum of its proper divisors (248202859).

1231155605 is an equidigital number, since it uses as much as digits as its factorization.

1231155605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328627.

The product of its (nonzero) digits is 4500, while the sum is 29.

The square root of 1231155605 is about 35087.8270202074. The cubic root of 1231155605 is about 1071.7767101603.

Adding to 1231155605 its reverse (5065511321), we get a palindrome (6296666926).

The spelling of 1231155605 in words is "one billion, two hundred thirty-one million, one hundred fifty-five thousand, six hundred five".