134181781 has 4 divisors (see below), whose sum is σ = 141244000. Its totient is φ = 127119564.

The previous prime is 134181779. The next prime is 134181787. The reversal of 134181781 is 187181431.

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, and also an emirpimes, since its reverse is a distinct semiprime: 187181431 = 139 ⋅1346629.

It is a cyclic number.

It is not a de Polignac number, because 134181781 - 2¹ = 134181779 is a prime.

It is a super-2 number, since 2×134181781² = 36009500704663922, 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 (134181787) 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, 3531081 + ... + 3531118.

It is an arithmetic number, because the mean of its divisors is an integer number (35311000).

Almost surely, 2^134181781 is an apocalyptic number.

It is an amenable number.

134181781 is a deficient number, since it is larger than the sum of its proper divisors (7062219).

134181781 is an equidigital number, since it uses as much as digits as its factorization.

134181781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7062218.

The product of its digits is 5376, while the sum is 34.

The square root of 134181781 is about 11583.6859850395. The cubic root of 134181781 is about 511.9542869445.

The spelling of 134181781 in words is "one hundred thirty-four million, one hundred eighty-one thousand, seven hundred eighty-one".