133471809 has 9 divisors (see below), whose sum is σ = 192842689. Its totient is φ = 88958100.

The previous prime is 133471801. The next prime is 133471841. The reversal of 133471809 is 908174331.

It is a happy number.

The square root of 133471809 is 11553.

It is a perfect power (a square), and thus also a powerful number.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 133471809 - 2³ = 133471801 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (133471801) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 32734 + ... + 36584.

Almost surely, 2^133471809 is an apocalyptic number.

133471809 is the 11553-rd square number.

133471809 is the 5777-th centered octagonal number.

It is an amenable number.

133471809 is a deficient number, since it is larger than the sum of its proper divisors (59370880).

133471809 is an frugal number, since it uses more digits than its factorization.

133471809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7708 (or 3854 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The cubic root of 133471809 is about 511.0497524203.

Multiplying 133471809 by its sum of digits (36), we get a square (4804985124 = 69318²).

The spelling of 133471809 in words is "one hundred thirty-three million, four hundred seventy-one thousand, eight hundred nine".