135551999 has 16 divisors (see below), whose sum is σ = 158145696. Its totient is φ = 114816000.

The previous prime is 135551989. The next prime is 135552013. The reversal of 135551999 is 999155531.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 135551999 - 2²⁰ = 134503423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135551939) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15299 + ... + 22475.

It is an arithmetic number, because the mean of its divisors is an integer number (9884106).

Almost surely, 2^135551999 is an apocalyptic number.

135551999 is a deficient number, since it is larger than the sum of its proper divisors (22593697).

135551999 is a wasteful number, since it uses less digits than its factorization.

135551999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7306.

The product of its digits is 273375, while the sum is 47.

The square root of 135551999 is about 11642.6800608795. The cubic root of 135551999 is about 513.6910220933.

The spelling of 135551999 in words is "one hundred thirty-five million, five hundred fifty-one thousand, nine hundred ninety-nine".