135388007721 has 12 divisors (see below), whose sum is σ = 196987905972. Its totient is φ = 89599848576.

The previous prime is 135388007707. The next prime is 135388007749. The reversal of 135388007721 is 127700883531.

135388007721 is a `hidden beast` number, since 13 + 538 + 80 + 0 + 7 + 7 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 97756275600 + 37631732121 = 312660^2 + 193989^2 .

It is not a de Polignac number, because 135388007721 - 2²⁹ = 134851136809 is a prime.

It is a super-2 number, since 2×135388007721² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (135388007791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 54900636 + ... + 54903101.

It is an arithmetic number, because the mean of its divisors is an integer number (16415658831).

Almost surely, 2^135388007721 is an apocalyptic number.

It is an amenable number.

135388007721 is a deficient number, since it is larger than the sum of its proper divisors (61599898251).

135388007721 is a wasteful number, since it uses less digits than its factorization.

135388007721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109803880 (or 109803877 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 45.

The spelling of 135388007721 in words is "one hundred thirty-five billion, three hundred eighty-eight million, seven thousand, seven hundred twenty-one".