1145321231 has 4 divisors (see below), whose sum is σ = 1147190232. Its totient is φ = 1143452232.

The previous prime is 1145321209. The next prime is 1145321279. The reversal of 1145321231 is 1321235411.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1321235411 = 1543 ⋅856277.

It is a cyclic number.

It is not a de Polignac number, because 1145321231 - 2⁶ = 1145321167 is a prime.

It is a super-2 number, since 2×1145321231² = 2623521444358710722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1145321197 and 1145321206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1145321201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 933581 + ... + 934806.

It is an arithmetic number, because the mean of its divisors is an integer number (286797558).

Almost surely, 2^1145321231 is an apocalyptic number.

1145321231 is a deficient number, since it is larger than the sum of its proper divisors (1869001).

1145321231 is an equidigital number, since it uses as much as digits as its factorization.

1145321231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1869000.

The product of its digits is 720, while the sum is 23.

The square root of 1145321231 is about 33842.5949211936. The cubic root of 1145321231 is about 1046.2667820844.

Adding to 1145321231 its reverse (1321235411), we get a palindrome (2466556642).

The spelling of 1145321231 in words is "one billion, one hundred forty-five million, three hundred twenty-one thousand, two hundred thirty-one".