194993815 has 4 divisors (see below), whose sum is σ = 233992584. Its totient is φ = 155995048.

The previous prime is 194993807. The next prime is 194993819. The reversal of 194993815 is 518399491.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 194993815 - 2³ = 194993807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (194993819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19499377 + ... + 19499386.

It is an arithmetic number, because the mean of its divisors is an integer number (58498146).

Almost surely, 2^194993815 is an apocalyptic number.

194993815 is a deficient number, since it is larger than the sum of its proper divisors (38998769).

194993815 is an equidigital number, since it uses as much as digits as its factorization.

194993815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38998768.

The product of its digits is 349920, while the sum is 49.

The square root of 194993815 is about 13964.0185834881. The cubic root of 194993815 is about 579.8828687369.

It can be divided in two parts, 194 and 993815, that added together give a square (994009 = 997²).

The spelling of 194993815 in words is "one hundred ninety-four million, nine hundred ninety-three thousand, eight hundred fifteen".