133673807681 has 4 divisors (see below), whose sum is σ = 137286613332. Its totient is φ = 130061002032.

The previous prime is 133673807677. The next prime is 133673807711. The reversal of 133673807681 is 186708376331.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 128321568400 + 5352239281 = 358220^2 + 73159^2 .

It is a cyclic number.

It is not a de Polignac number, because 133673807681 - 2² = 133673807677 is a prime.

It is a super-2 number, since 2×133673807681² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (133673807081) 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, 1806402770 + ... + 1806402843.

It is an arithmetic number, because the mean of its divisors is an integer number (34321653333).

Almost surely, 2^133673807681 is an apocalyptic number.

It is an amenable number.

133673807681 is a deficient number, since it is larger than the sum of its proper divisors (3612805651).

133673807681 is an equidigital number, since it uses as much as digits as its factorization.

133673807681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3612805650.

The product of its (nonzero) digits is 3048192, while the sum is 53.

The spelling of 133673807681 in words is "one hundred thirty-three billion, six hundred seventy-three million, eight hundred seven thousand, six hundred eighty-one".