13542539621 has 4 divisors (see below), whose sum is σ = 14584273452. Its totient is φ = 12500805792.

The previous prime is 13542539597. The next prime is 13542539629. The reversal of 13542539621 is 12693524531.

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 7619544100 + 5922995521 = 87290^2 + 76961^2 .

It is a cyclic number.

It is not a de Polignac number, because 13542539621 - 2⁶ = 13542539557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13542539629) 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, 520866896 + ... + 520866921.

It is an arithmetic number, because the mean of its divisors is an integer number (3646068363).

Almost surely, 2^13542539621 is an apocalyptic number.

It is an amenable number.

13542539621 is a deficient number, since it is larger than the sum of its proper divisors (1041733831).

13542539621 is a wasteful number, since it uses less digits than its factorization.

13542539621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1041733830.

The product of its digits is 194400, while the sum is 41.

The spelling of 13542539621 in words is "thirteen billion, five hundred forty-two million, five hundred thirty-nine thousand, six hundred twenty-one".