1231043515321 has 4 divisors (see below), whose sum is σ = 1231069168000. Its totient is φ = 1231017862644.

The previous prime is 1231043515307. The next prime is 1231043515393. The reversal of 1231043515321 is 1235153401321.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1231043515321 - 2¹³ = 1231043507129 is a prime.

It is a super-2 number, since 2×1231043515321² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231043515301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12754221 + ... + 12850378.

It is an arithmetic number, because the mean of its divisors is an integer number (307767292000).

Almost surely, 2^{1231043515321} is an apocalyptic number.

It is an amenable number.

1231043515321 is a deficient number, since it is larger than the sum of its proper divisors (25652679).

1231043515321 is an equidigital number, since it uses as much as digits as its factorization.

1231043515321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25652678.

The product of its (nonzero) digits is 10800, while the sum is 31.

Adding to 1231043515321 its reverse (1235153401321), we get a palindrome (2466196916642).

The spelling of 1231043515321 in words is "one trillion, two hundred thirty-one billion, forty-three million, five hundred fifteen thousand, three hundred twenty-one".