13540452421 has 4 divisors (see below), whose sum is σ = 13680044812. Its totient is φ = 13400860032.

The previous prime is 13540452407. The next prime is 13540452427. The reversal of 13540452421 is 12425404531.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12425404531 = 31 ⋅400819501.

It can be written as a sum of positive squares in 2 ways, for example, as 8774068900 + 4766383521 = 93670^2 + 69039^2 .

It is a cyclic number.

It is not a de Polignac number, because 13540452421 - 2⁷ = 13540452293 is a prime.

It is a super-2 number, since 2×13540452421² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13540452427) 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, 69796050 + ... + 69796243.

It is an arithmetic number, because the mean of its divisors is an integer number (3420011203).

Almost surely, 2^13540452421 is an apocalyptic number.

It is an amenable number.

13540452421 is a deficient number, since it is larger than the sum of its proper divisors (139592391).

13540452421 is an equidigital number, since it uses as much as digits as its factorization.

13540452421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139592390.

The product of its (nonzero) digits is 19200, while the sum is 31.

Adding to 13540452421 its reverse (12425404531), we get a palindrome (25965856952).

The spelling of 13540452421 in words is "thirteen billion, five hundred forty million, four hundred fifty-two thousand, four hundred twenty-one".