191681045 has 4 divisors (see below), whose sum is σ = 230017260. Its totient is φ = 153344832.

The previous prime is 191681023. The next prime is 191681047. The reversal of 191681045 is 540186191.

191681045 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 540186191 = 31 ⋅17425361.

It can be written as a sum of positive squares in 2 ways, for example, as 24780484 + 166900561 = 4978^2 + 12919^2 .

It is a cyclic number.

It is not a de Polignac number, because 191681045 - 2⁸ = 191680789 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 191680996 and 191681014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191681047) 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, 19168100 + ... + 19168109.

It is an arithmetic number, because the mean of its divisors is an integer number (57504315).

Almost surely, 2^191681045 is an apocalyptic number.

It is an amenable number.

191681045 is a deficient number, since it is larger than the sum of its proper divisors (38336215).

191681045 is an equidigital number, since it uses as much as digits as its factorization.

191681045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38336214.

The product of its (nonzero) digits is 8640, while the sum is 35.

The square root of 191681045 is about 13844.8923795023. The cubic root of 191681045 is about 576.5801977930.

The spelling of 191681045 in words is "one hundred ninety-one million, six hundred eighty-one thousand, forty-five".