194005639 has 4 divisors (see below), whose sum is σ = 194108040. Its totient is φ = 193903240.

The previous prime is 194005633. The next prime is 194005661. The reversal of 194005639 is 936500491.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 936500491 = 1423 ⋅658117.

It is a cyclic number.

It is not a de Polignac number, because 194005639 - 2³ = 194005631 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 194005598 and 194005607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (194005631) 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, 48304 + ... + 52165.

It is an arithmetic number, because the mean of its divisors is an integer number (48527010).

Almost surely, 2^194005639 is an apocalyptic number.

194005639 is a deficient number, since it is larger than the sum of its proper divisors (102401).

194005639 is a wasteful number, since it uses less digits than its factorization.

194005639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102400.

The product of its (nonzero) digits is 29160, while the sum is 37.

The square root of 194005639 is about 13928.5907040160. The cubic root of 194005639 is about 578.9016460776.

The spelling of 194005639 in words is "one hundred ninety-four million, five thousand, six hundred thirty-nine".