1231413233521 has 4 divisors (see below), whose sum is σ = 1236698269092. Its totient is φ = 1226128197952.

The previous prime is 1231413233507. The next prime is 1231413233563. The reversal of 1231413233521 is 1253323141321.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 425971602225 + 805441631296 = 652665^2 + 897464^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231413233521 - 2¹⁵ = 1231413200753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231413233581) 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, 2642517436 + ... + 2642517901.

It is an arithmetic number, because the mean of its divisors is an integer number (309174567273).

Almost surely, 2^{1231413233521} is an apocalyptic number.

It is an amenable number.

1231413233521 is a deficient number, since it is larger than the sum of its proper divisors (5285035571).

1231413233521 is an equidigital number, since it uses as much as digits as its factorization.

1231413233521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5285035570.

The product of its digits is 12960, while the sum is 31.

Adding to 1231413233521 its reverse (1253323141321), we get a palindrome (2484736374842).

The spelling of 1231413233521 in words is "one trillion, two hundred thirty-one billion, four hundred thirteen million, two hundred thirty-three thousand, five hundred twenty-one".