133445681 has 4 divisors (see below), whose sum is σ = 133632000. Its totient is φ = 133259364.

The previous prime is 133445677. The next prime is 133445687. The reversal of 133445681 is 186544331.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 133445681 - 2² = 133445677 is a prime.

It is a super-2 number, since 2×133445681² = 35615499555107522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (133445687) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 92081 + ... + 93518.

It is an arithmetic number, because the mean of its divisors is an integer number (33408000).

Almost surely, 2^133445681 is an apocalyptic number.

It is an amenable number.

133445681 is a deficient number, since it is larger than the sum of its proper divisors (186319).

133445681 is an equidigital number, since it uses as much as digits as its factorization.

133445681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186318.

The product of its digits is 34560, while the sum is 35.

The square root of 133445681 is about 11551.8691561150. The cubic root of 133445681 is about 511.0164031075.

The spelling of 133445681 in words is "one hundred thirty-three million, four hundred forty-five thousand, six hundred eighty-one".