135621523 has 4 divisors (see below), whose sum is σ = 135888480. Its totient is φ = 135354568.

The previous prime is 135621511. The next prime is 135621533. The reversal of 135621523 is 325126531.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 325126531 = 283 ⋅1148857.

It is a cyclic number.

It is not a de Polignac number, because 135621523 - 2⁵ = 135621491 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 135621491 and 135621500.

It is not an unprimeable number, because it can be changed into a prime (135621503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 132715 + ... + 133732.

It is an arithmetic number, because the mean of its divisors is an integer number (33972120).

Almost surely, 2^135621523 is an apocalyptic number.

135621523 is a deficient number, since it is larger than the sum of its proper divisors (266957).

135621523 is an equidigital number, since it uses as much as digits as its factorization.

135621523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266956.

The product of its digits is 5400, while the sum is 28.

The square root of 135621523 is about 11645.6654167978. The cubic root of 135621523 is about 513.7788303410.

The spelling of 135621523 in words is "one hundred thirty-five million, six hundred twenty-one thousand, five hundred twenty-three".