133655921 has 32 divisors (see below), whose sum is σ = 172523520. Its totient is φ = 100843776.

The previous prime is 133655917. The next prime is 133655923. The reversal of 133655921 is 129556331.

It is not a de Polignac number, because 133655921 - 2² = 133655917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (133655923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 128120 + ... + 129158.

It is an arithmetic number, because the mean of its divisors is an integer number (5391360).

Almost surely, 2^133655921 is an apocalyptic number.

It is an amenable number.

133655921 is a deficient number, since it is larger than the sum of its proper divisors (38867599).

133655921 is a wasteful number, since it uses less digits than its factorization.

133655921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1133.

The product of its digits is 24300, while the sum is 35.

The square root of 133655921 is about 11560.9654008651. The cubic root of 133655921 is about 511.2846263932.

The spelling of 133655921 in words is "one hundred thirty-three million, six hundred fifty-five thousand, nine hundred twenty-one".