194115409 has 4 divisors (see below), whose sum is σ = 194404516. Its totient is φ = 193826304.

The previous prime is 194115391. The next prime is 194115421. The reversal of 194115409 is 904511491.

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 150185025 + 43930384 = 12255^2 + 6628^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-194115409 is a prime.

It is a super-2 number, since 2×194115409² = 75361584022474562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (194115709) 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, 143544 + ... + 144889.

It is an arithmetic number, because the mean of its divisors is an integer number (48601129).

Almost surely, 2^194115409 is an apocalyptic number.

It is an amenable number.

194115409 is a deficient number, since it is larger than the sum of its proper divisors (289107).

194115409 is an equidigital number, since it uses as much as digits as its factorization.

194115409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289106.

The product of its (nonzero) digits is 6480, while the sum is 34.

The square root of 194115409 is about 13932.5306028733. The cubic root of 194115409 is about 579.0108079432.

The spelling of 194115409 in words is "one hundred ninety-four million, one hundred fifteen thousand, four hundred nine".