133555121 has 16 divisors (see below), whose sum is σ = 158979840. Its totient is φ = 109771200.

The previous prime is 133555117. The next prime is 133555127. The reversal of 133555121 is 121555331.

It is a happy number.

It is not a de Polignac number, because 133555121 - 2² = 133555117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (133555127) 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, 28475 + ... + 32831.

It is an arithmetic number, because the mean of its divisors is an integer number (9936240).

Almost surely, 2^133555121 is an apocalyptic number.

It is an amenable number.

133555121 is a deficient number, since it is larger than the sum of its proper divisors (25424719).

133555121 is a wasteful number, since it uses less digits than its factorization.

133555121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4544.

The product of its digits is 2250, while the sum is 26.

The square root of 133555121 is about 11556.6050810781. The cubic root of 133555121 is about 511.1560613148.

The spelling of 133555121 in words is "one hundred thirty-three million, five hundred fifty-five thousand, one hundred twenty-one".