191555945 has 12 divisors (see below), whose sum is σ = 267396804. Its totient is φ = 131352480.

The previous prime is 191555911. The next prime is 191555951. The reversal of 191555945 is 549555191.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 25120144 + 166435801 = 5012^2 + 12901^2 .

It is a de Polignac number, because none of the positive numbers 2^k-191555945 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 191555896 and 191555905.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 390686 + ... + 391175.

It is an arithmetic number, because the mean of its divisors is an integer number (22283067).

Almost surely, 2^191555945 is an apocalyptic number.

It is an amenable number.

191555945 is a deficient number, since it is larger than the sum of its proper divisors (75840859).

191555945 is an equidigital number, since it uses as much as digits as its factorization.

191555945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 781880 (or 781873 counting only the distinct ones).

The product of its digits is 202500, while the sum is 44.

The square root of 191555945 is about 13840.3737305031. The cubic root of 191555945 is about 576.4547361087.

The spelling of 191555945 in words is "one hundred ninety-one million, five hundred fifty-five thousand, nine hundred forty-five".