194692409 has 4 divisors (see below), whose sum is σ = 199954404. Its totient is φ = 189430416.

The previous prime is 194692391. The next prime is 194692423. The reversal of 194692409 is 904296491.

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 142086400 + 52606009 = 11920^2 + 7253^2 .

It is a cyclic number.

It is not a de Polignac number, because 194692409 - 2¹² = 194688313 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 194692409.

It is not an unprimeable number, because it can be changed into a prime (194692429) 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, 2630942 + ... + 2631015.

It is an arithmetic number, because the mean of its divisors is an integer number (49988601).

Almost surely, 2^194692409 is an apocalyptic number.

It is an amenable number.

194692409 is a deficient number, since it is larger than the sum of its proper divisors (5261995).

194692409 is an equidigital number, since it uses as much as digits as its factorization.

194692409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5261994.

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 194692409 is about 13953.2221726740. Note that the first 3 decimals coincide. The cubic root of 194692409 is about 579.5839356534.

The spelling of 194692409 in words is "one hundred ninety-four million, six hundred ninety-two thousand, four hundred nine".