135421521 has 4 divisors (see below), whose sum is σ = 180562032. Its totient is φ = 90281012.

The previous prime is 135421501. The next prime is 135421553. The reversal of 135421521 is 125124531.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 135421521 - 2⁶ = 135421457 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 135421491 and 135421500.

It is not an unprimeable number, because it can be changed into a prime (135421501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22570251 + ... + 22570256.

It is an arithmetic number, because the mean of its divisors is an integer number (45140508).

Almost surely, 2^135421521 is an apocalyptic number.

It is an amenable number.

135421521 is a deficient number, since it is larger than the sum of its proper divisors (45140511).

135421521 is an equidigital number, since it uses as much as digits as its factorization.

135421521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45140510.

The product of its digits is 1200, while the sum is 24.

The square root of 135421521 is about 11637.0752768898. The cubic root of 135421521 is about 513.5261483556.

The spelling of 135421521 in words is "one hundred thirty-five million, four hundred twenty-one thousand, five hundred twenty-one".