135818147221 has 16 divisors (see below), whose sum is σ = 139352348160. Its totient is φ = 132338208240.

The previous prime is 135818147219. The next prime is 135818147233. The reversal of 135818147221 is 122741818531.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 135818147221 - 2¹ = 135818147219 is a prime.

It is a super-2 number, since 2×135818147221² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135818147321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2038786 + ... + 2104348.

It is an arithmetic number, because the mean of its divisors is an integer number (8709521760).

Almost surely, 2^135818147221 is an apocalyptic number.

It is an amenable number.

135818147221 is a deficient number, since it is larger than the sum of its proper divisors (3534200939).

135818147221 is a wasteful number, since it uses less digits than its factorization.

135818147221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65976.

The product of its digits is 107520, while the sum is 43.

The spelling of 135818147221 in words is "one hundred thirty-five billion, eight hundred eighteen million, one hundred forty-seven thousand, two hundred twenty-one".