135221211021 has 96 divisors (see below), whose sum is σ = 204069888000. Its totient is φ = 79553021184.

The previous prime is 135221210987. The next prime is 135221211023. The reversal of 135221211021 is 120112122531.

It is not a de Polignac number, because 135221211021 - 2¹⁴ = 135221194637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135221211023) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 205191190 + ... + 205191848.

It is an arithmetic number, because the mean of its divisors is an integer number (2125728000).

Almost surely, 2^135221211021 is an apocalyptic number.

It is an amenable number.

135221211021 is a deficient number, since it is larger than the sum of its proper divisors (68848676979).

135221211021 is a wasteful number, since it uses less digits than its factorization.

135221211021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 923 (or 910 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 21.

Adding to 135221211021 its reverse (120112122531), we get a palindrome (255333333552).

The spelling of 135221211021 in words is "one hundred thirty-five billion, two hundred twenty-one million, two hundred eleven thousand, twenty-one".