135221919 has 20 divisors (see below), whose sum is σ = 210343896. Its totient is φ = 77265552.

The previous prime is 135221897. The next prime is 135221941. The reversal of 135221919 is 919122531.

135221919 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (135221897) and next prime (135221941).

It is not a de Polignac number, because 135221919 - 2¹⁶ = 135156383 is a prime.

It is a super-2 number, since 2×135221919² = 36569934756085122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 135221919.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135221959) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2184 + ... + 16589.

Almost surely, 2^135221919 is an apocalyptic number.

135221919 is a deficient number, since it is larger than the sum of its proper divisors (75121977).

135221919 is an frugal number, since it uses more digits than its factorization.

135221919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18804 (or 18783 counting only the distinct ones).

The product of its digits is 4860, while the sum is 33.

The square root of 135221919 is about 11628.4959904538. The cubic root of 135221919 is about 513.2737235649.

The spelling of 135221919 in words is "one hundred thirty-five million, two hundred twenty-one thousand, nine hundred nineteen".