133523865 has 48 divisors (see below), whose sum is σ = 246250368. Its totient is φ = 66697728.

The previous prime is 133523857. The next prime is 133523867. The reversal of 133523865 is 568325331.

It is not a de Polignac number, because 133523865 - 2³ = 133523857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (133523867) 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 47 ways as a sum of consecutive naturals, for example, 265204 + ... + 265706.

It is an arithmetic number, because the mean of its divisors is an integer number (5130216).

Almost surely, 2^133523865 is an apocalyptic number.

133523865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

133523865 is a deficient number, since it is larger than the sum of its proper divisors (112726503).

133523865 is a wasteful number, since it uses less digits than its factorization.

133523865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 878 (or 875 counting only the distinct ones).

The product of its digits is 64800, while the sum is 36.

The square root of 133523865 is about 11555.2527016937. The cubic root of 133523865 is about 511.1161827982.

It can be divided in two parts, 1335 and 23865, that added together give a triangular number (25200 = T₂₂₄).

The spelling of 133523865 in words is "one hundred thirty-three million, five hundred twenty-three thousand, eight hundred sixty-five".