133815231 has 36 divisors (see below), whose sum is σ = 214700304. Its totient is φ = 80245440.

The previous prime is 133815223. The next prime is 133815257. The reversal of 133815231 is 132518331.

133815231 is a `hidden beast` number, since 133 + 8 + 1 + 523 + 1 = 666.

It is not a de Polignac number, because 133815231 - 2³ = 133815223 is a prime.

It is a super-3 number, since 3×133815231³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 133815195 and 133815204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133815631) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 111571 + ... + 112763.

Almost surely, 2^133815231 is an apocalyptic number.

133815231 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

133815231 is a deficient number, since it is larger than the sum of its proper divisors (80885073).

133815231 is a wasteful number, since it uses less digits than its factorization.

133815231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1324 (or 1310 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 133815231 is about 11567.8533445061. The cubic root of 133815231 is about 511.4876861413.

The spelling of 133815231 in words is "one hundred thirty-three million, eight hundred fifteen thousand, two hundred thirty-one".