133172981 has 8 divisors (see below), whose sum is σ = 134957760. Its totient is φ = 131400288.

The previous prime is 133172969. The next prime is 133172987. The reversal of 133172981 is 189271331.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 133172981 - 2¹⁸ = 132910837 is a prime.

It is a super-2 number, since 2×133172981² = 35470085736852722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133172987) 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, 20345 + ... + 26081.

It is an arithmetic number, because the mean of its divisors is an integer number (16869720).

Almost surely, 2^133172981 is an apocalyptic number.

It is an amenable number.

133172981 is a deficient number, since it is larger than the sum of its proper divisors (1784779).

133172981 is a wasteful number, since it uses less digits than its factorization.

133172981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6043.

The product of its digits is 9072, while the sum is 35.

The square root of 133172981 is about 11540.0598352002. The cubic root of 133172981 is about 510.6680735982.

The spelling of 133172981 in words is "one hundred thirty-three million, one hundred seventy-two thousand, nine hundred eighty-one".