135440424521 has 4 divisors (see below), whose sum is σ = 135441533844. Its totient is φ = 135439315200.

The previous prime is 135440424503. The next prime is 135440424527. The reversal of 135440424521 is 125424044531.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 63498456121 + 71941968400 = 251989^2 + 268220^2 .

It is a cyclic number.

It is not a de Polignac number, because 135440424521 - 2¹⁴ = 135440408137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (135440424527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 345140 + ... + 624501.

It is an arithmetic number, because the mean of its divisors is an integer number (33860383461).

Almost surely, 2^135440424521 is an apocalyptic number.

It is an amenable number.

135440424521 is a deficient number, since it is larger than the sum of its proper divisors (1109323).

135440424521 is an equidigital number, since it uses as much as digits as its factorization.

135440424521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1109322.

The product of its (nonzero) digits is 76800, while the sum is 35.

The spelling of 135440424521 in words is "one hundred thirty-five billion, four hundred forty million, four hundred twenty-four thousand, five hundred twenty-one".