133261681 has 8 divisors (see below), whose sum is σ = 153411840. Its totient is φ = 113389728.

The previous prime is 133261669. The next prime is 133261717. The reversal of 133261681 is 186162331.

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 133261681 - 2⁷ = 133261553 is a prime.

It is a super-2 number, since 2×133261681² = 35517351245891522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (133261621) 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, 68521 + ... + 70438.

It is an arithmetic number, because the mean of its divisors is an integer number (19176480).

Almost surely, 2^133261681 is an apocalyptic number.

It is an amenable number.

133261681 is a deficient number, since it is larger than the sum of its proper divisors (20150159).

133261681 is a wasteful number, since it uses less digits than its factorization.

133261681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139103.

The product of its digits is 5184, while the sum is 31.

The square root of 133261681 is about 11543.9023298017. The cubic root of 133261681 is about 510.7814254332.

The spelling of 133261681 in words is "one hundred thirty-three million, two hundred sixty-one thousand, six hundred eighty-one".