1231320065 has 8 divisors (see below), whose sum is σ = 1541827008. Its totient is φ = 942227440.

The previous prime is 1231320043. The next prime is 1231320067. The reversal of 1231320065 is 5600231321.

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

It is not a de Polignac number, because 1231320065 - 2²² = 1227125761 is a prime.

It is a super-2 number, since 2×1231320065² = 3032298204943208450, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1231320065.

It is not an unprimeable number, because it can be changed into a prime (1231320067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5353451 + ... + 5353680.

It is an arithmetic number, because the mean of its divisors is an integer number (192728376).

Almost surely, 2^1231320065 is an apocalyptic number.

It is an amenable number.

1231320065 is a deficient number, since it is larger than the sum of its proper divisors (310506943).

1231320065 is a wasteful number, since it uses less digits than its factorization.

1231320065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10707159.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 1231320065 is about 35090.1704897540. The cubic root of 1231320065 is about 1071.8244313282.

Adding to 1231320065 its reverse (5600231321), we get a palindrome (6831551386).

The spelling of 1231320065 in words is "one billion, two hundred thirty-one million, three hundred twenty thousand, sixty-five".