133611540 has 24 divisors (see below), whose sum is σ = 374112480. Its totient is φ = 35629728.

The previous prime is 133611529. The next prime is 133611547. The reversal of 133611540 is 45116331.

Added to its reverse (45116331) it gives a triangular number (178727871 = T₁₈₉₀₆).

It is a self number, because there is not a number n which added to its sum of digits gives 133611540.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133611547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1113370 + ... + 1113489.

It is an arithmetic number, because the mean of its divisors is an integer number (15588020).

Almost surely, 2^133611540 is an apocalyptic number.

133611540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

133611540 is an abundant number, since it is smaller than the sum of its proper divisors (240500940).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

133611540 is a wasteful number, since it uses less digits than its factorization.

133611540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2226871 (or 2226869 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 133611540 is about 11559.0458083702. The cubic root of 133611540 is about 511.2280287384.

Adding to 133611540 its reverse (45116331), we get a palindrome (178727871).

The spelling of 133611540 in words is "one hundred thirty-three million, six hundred eleven thousand, five hundred forty".