191939947 has 4 divisors (see below), whose sum is σ = 193089456. Its totient is φ = 190790440.

The previous prime is 191939903. The next prime is 191939959. The reversal of 191939947 is 749939191.

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 191939947 - 2¹¹ = 191937899 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 191939894 and 191939903.

It is not an unprimeable number, because it can be changed into a prime (191939987) 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, 574504 + ... + 574837.

It is an arithmetic number, because the mean of its divisors is an integer number (48272364).

Almost surely, 2^191939947 is an apocalyptic number.

191939947 is a deficient number, since it is larger than the sum of its proper divisors (1149509).

191939947 is a wasteful number, since it uses less digits than its factorization.

191939947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1149508.

The product of its digits is 551124, while the sum is 52.

The square root of 191939947 is about 13854.2393150977. The cubic root of 191939947 is about 576.8396750362.

The spelling of 191939947 in words is "one hundred ninety-one million, nine hundred thirty-nine thousand, nine hundred forty-seven".