13531220405 has 24 divisors (see below), whose sum is σ = 17156823192. Its totient is φ = 10243408896.

The previous prime is 13531220387. The next prime is 13531220501. The reversal of 13531220405 is 50402213531.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5001035524 + 8530184881 = 70718^2 + 92359^2 .

It is not a de Polignac number, because 13531220405 - 2¹⁶ = 13531154869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1759649 + ... + 1767321.

It is an arithmetic number, because the mean of its divisors is an integer number (714867633).

Almost surely, 2^13531220405 is an apocalyptic number.

It is an amenable number.

13531220405 is a deficient number, since it is larger than the sum of its proper divisors (3625602787).

13531220405 is an equidigital number, since it uses as much as digits as its factorization.

13531220405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8693 (or 8674 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 26.

Adding to 13531220405 its reverse (50402213531), we get a palindrome (63933433936).

The spelling of 13531220405 in words is "thirteen billion, five hundred thirty-one million, two hundred twenty thousand, four hundred five".