135555121 has 4 divisors (see below), whose sum is σ = 145982452. Its totient is φ = 125127792.

The previous prime is 135555071. The next prime is 135555131. The reversal of 135555121 is 121555531.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 49900096 + 85655025 = 7064^2 + 9255^2 .

It is a cyclic number.

It is not a de Polignac number, because 135555121 - 2⁹ = 135554609 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 135555121.

It is not an unprimeable number, because it can be changed into a prime (135555131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5213646 + ... + 5213671.

It is an arithmetic number, because the mean of its divisors is an integer number (36495613).

Almost surely, 2^135555121 is an apocalyptic number.

It is an amenable number.

135555121 is a deficient number, since it is larger than the sum of its proper divisors (10427331).

135555121 is a wasteful number, since it uses less digits than its factorization.

135555121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10427330.

The product of its digits is 3750, while the sum is 28.

The square root of 135555121 is about 11642.8141357663. The cubic root of 135555121 is about 513.6949657977.

The spelling of 135555121 in words is "one hundred thirty-five million, five hundred fifty-five thousand, one hundred twenty-one".