1231276321 has 8 divisors (see below), whose sum is σ = 1386540288. Its totient is φ = 1083234000.

The previous prime is 1231276297. The next prime is 1231276349. The reversal of 1231276321 is 1236721321.

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 1231276321 - 2¹¹ = 1231274273 is a prime.

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 1231276321.

It is not an unprimeable number, because it can be changed into a prime (1231276021) 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 7 ways as a sum of consecutive naturals, for example, 1805050 + ... + 1805731.

It is an arithmetic number, because the mean of its divisors is an integer number (173317536).

Almost surely, 2^1231276321 is an apocalyptic number.

1231276321 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1231276321 is a deficient number, since it is larger than the sum of its proper divisors (155263967).

1231276321 is a wasteful number, since it uses less digits than its factorization.

1231276321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3610823.

The product of its digits is 3024, while the sum is 28.

The square root of 1231276321 is about 35089.5471757616. The cubic root of 1231276321 is about 1071.8117385971.

Adding to 1231276321 its reverse (1236721321), we get a palindrome (2467997642).

The spelling of 1231276321 in words is "one billion, two hundred thirty-one million, two hundred seventy-six thousand, three hundred twenty-one".