133503921 has 24 divisors (see below), whose sum is σ = 195908544. Its totient is φ = 87597600.

The previous prime is 133503919. The next prime is 133503947. The reversal of 133503921 is 129305331.

It is a happy number.

133503921 is a `hidden beast` number, since 133 + 503 + 9 + 21 = 666.

It is not a de Polignac number, because 133503921 - 2¹ = 133503919 is a prime.

It is not an unprimeable number, because it can be changed into a prime (133503911) 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 23 ways as a sum of consecutive naturals, for example, 206020 + ... + 206666.

It is an arithmetic number, because the mean of its divisors is an integer number (8162856).

Almost surely, 2^133503921 is an apocalyptic number.

It is an amenable number.

133503921 is a deficient number, since it is larger than the sum of its proper divisors (62404623).

133503921 is a wasteful number, since it uses less digits than its factorization.

133503921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 981 (or 978 counting only the distinct ones).

The product of its (nonzero) digits is 2430, while the sum is 27.

The square root of 133503921 is about 11554.3896853101. The cubic root of 133503921 is about 511.0907336429.

It can be divided in two parts, 13350 and 3921, that added together give a palindrome (17271).

The spelling of 133503921 in words is "one hundred thirty-three million, five hundred three thousand, nine hundred twenty-one".