135221913 has 8 divisors (see below), whose sum is σ = 200328800. Its totient is φ = 90147924.

The previous prime is 135221897. The next prime is 135221941. The reversal of 135221913 is 319122531.

It is not a de Polignac number, because 135221913 - 2⁴ = 135221897 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 5008219 = 135221913 / (1 + 3 + 5 + 2 + 2 + 1 + 9 + 1 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (135221953) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2504083 + ... + 2504136.

It is an arithmetic number, because the mean of its divisors is an integer number (25041100).

Almost surely, 2^135221913 is an apocalyptic number.

It is an amenable number.

135221913 is a deficient number, since it is larger than the sum of its proper divisors (65106887).

135221913 is an equidigital number, since it uses as much as digits as its factorization.

135221913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5008228 (or 5008222 counting only the distinct ones).

The product of its digits is 1620, while the sum is 27.

The square root of 135221913 is about 11628.4957324669. The cubic root of 135221913 is about 513.2737159733.

The spelling of 135221913 in words is "one hundred thirty-five million, two hundred twenty-one thousand, nine hundred thirteen".