133873509 has 16 divisors (see below), whose sum is σ = 222543360. Its totient is φ = 69544560.

The previous prime is 133873507. The next prime is 133873513. The reversal of 133873509 is 905378331.

It is not a de Polignac number, because 133873509 - 2¹ = 133873507 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133873507) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 289539 + ... + 290000.

It is an arithmetic number, because the mean of its divisors is an integer number (13908960).

Almost surely, 2^133873509 is an apocalyptic number.

It is an amenable number.

133873509 is a deficient number, since it is larger than the sum of its proper divisors (88669851).

133873509 is a wasteful number, since it uses less digits than its factorization.

133873509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 579560.

The product of its (nonzero) digits is 68040, while the sum is 39.

The square root of 133873509 is about 11570.3720337766. The cubic root of 133873509 is about 511.5619281960.

It can be divided in two parts, 1338 and 73509, that added together give a palindrome (74847).

The spelling of 133873509 in words is "one hundred thirty-three million, eight hundred seventy-three thousand, five hundred nine".