133505281 has 8 divisors (see below), whose sum is σ = 164314304. Its totient is φ = 105630480.

The previous prime is 133505269. The next prime is 133505293. The reversal of 133505281 is 182505331.

It is an interprime number because it is at equal distance from previous prime (133505269) and next prime (133505293).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-133505281 is a prime.

It is a super-2 number, since 2×133505281² = 35647320109777922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (133505231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 733455 + ... + 733636.

It is an arithmetic number, because the mean of its divisors is an integer number (20539288).

Almost surely, 2^133505281 is an apocalyptic number.

It is an amenable number.

133505281 is a deficient number, since it is larger than the sum of its proper divisors (30809023).

133505281 is a wasteful number, since it uses less digits than its factorization.

133505281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1467111.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 133505281 is about 11554.4485372518. The cubic root of 133505281 is about 511.0924691251.

Subtracting 133505281 from its reverse (182505331), we obtain a triangular number (49000050 = T₉₈₉₉).

The spelling of 133505281 in words is "one hundred thirty-three million, five hundred five thousand, two hundred eighty-one".