194040921 has 4 divisors (see below), whose sum is σ = 258721232. Its totient is φ = 129360612.

The previous prime is 194040871. The next prime is 194040967. The reversal of 194040921 is 129040491.

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.

It is not a de Polignac number, because 194040921 - 2⁹ = 194040409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (194040991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32340151 + ... + 32340156.

It is an arithmetic number, because the mean of its divisors is an integer number (64680308).

Almost surely, 2^194040921 is an apocalyptic number.

It is an amenable number.

194040921 is a deficient number, since it is larger than the sum of its proper divisors (64680311).

194040921 is an equidigital number, since it uses as much as digits as its factorization.

194040921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64680310.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 194040921 is about 13929.8571780187. The cubic root of 194040921 is about 578.9367371020.

The spelling of 194040921 in words is "one hundred ninety-four million, forty thousand, nine hundred twenty-one".