133531555 has 16 divisors (see below), whose sum is σ = 164381184. Its totient is φ = 104076000.

The previous prime is 133531553. The next prime is 133531579. The reversal of 133531555 is 555135331.

It is a happy number.

It is not a de Polignac number, because 133531555 - 2¹ = 133531553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (133531553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 161052 + ... + 161878.

It is an arithmetic number, because the mean of its divisors is an integer number (10273824).

Almost surely, 2^133531555 is an apocalyptic number.

133531555 is a deficient number, since it is larger than the sum of its proper divisors (30849629).

133531555 is an equidigital number, since it uses as much as digits as its factorization.

133531555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1626.

The product of its digits is 16875, while the sum is 31.

The square root of 133531555 is about 11555.5854460084. The cubic root of 133531555 is about 511.1259947969.

Adding to 133531555 its reverse (555135331), we get a palindrome (688666886).

The spelling of 133531555 in words is "one hundred thirty-three million, five hundred thirty-one thousand, five hundred fifty-five".