135909621 has 12 divisors (see below), whose sum is σ = 201620172. Its totient is φ = 88157376.

The previous prime is 135909619. The next prime is 135909643. The reversal of 135909621 is 126909531.

135909621 is a `hidden beast` number, since 1 + 3 + 590 + 9 + 62 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 94770225 + 41139396 = 9735^2 + 6414^2 .

It is not a de Polignac number, because 135909621 - 2¹ = 135909619 is a prime.

It is a super-3 number, since 3×135909621³ (a number of 25 digits) contains 333 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135909601) 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 11 ways as a sum of consecutive naturals, for example, 203736 + ... + 204401.

It is an arithmetic number, because the mean of its divisors is an integer number (16801681).

Almost surely, 2^135909621 is an apocalyptic number.

It is an amenable number.

135909621 is a deficient number, since it is larger than the sum of its proper divisors (65710551).

135909621 is a wasteful number, since it uses less digits than its factorization.

135909621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 408180 (or 408177 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 36.

The square root of 135909621 is about 11658.0281780411. The cubic root of 135909621 is about 514.1423762904.

The spelling of 135909621 in words is "one hundred thirty-five million, nine hundred nine thousand, six hundred twenty-one".