133656720 has 240 divisors, whose sum is σ = 460470528. Its totient is φ = 32030720.

The previous prime is 133656709. The next prime is 133656727. The reversal of 133656720 is 27656331.

It is a Cunningham number, because it is equal to 11561²-1.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-3 number, since 3×133656720³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133656727) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2843737 + ... + 2843783.

Almost surely, 2^133656720 is an apocalyptic number.

133656720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 133656720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (230235264).

133656720 is an abundant number, since it is smaller than the sum of its proper divisors (326813808).

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

133656720 is a wasteful number, since it uses less digits than its factorization.

133656720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138 (or 115 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 33.

The square root of 133656720 is about 11560.9999567511. Note that the first 4 decimals coincide. The cubic root of 133656720 is about 511.2856452173.

The spelling of 133656720 in words is "one hundred thirty-three million, six hundred fifty-six thousand, seven hundred twenty".