191713421 has 4 divisors (see below), whose sum is σ = 192227772. Its totient is φ = 191199072.

The previous prime is 191713411. The next prime is 191713447. The reversal of 191713421 is 124317191.

191713421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 124317191 = 211 ⋅589181.

It can be written as a sum of positive squares in 2 ways, for example, as 79459396 + 112254025 = 8914^2 + 10595^2 .

It is a cyclic number.

It is not a de Polignac number, because 191713421 - 2¹⁰ = 191712397 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 (191713411) 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, 256616 + ... + 257361.

It is an arithmetic number, because the mean of its divisors is an integer number (48056943).

Almost surely, 2^191713421 is an apocalyptic number.

It is an amenable number.

191713421 is a deficient number, since it is larger than the sum of its proper divisors (514351).

191713421 is an equidigital number, since it uses as much as digits as its factorization.

191713421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514350.

The product of its digits is 1512, while the sum is 29.

The square root of 191713421 is about 13846.0615699917. The cubic root of 191713421 is about 576.6126585050.

The spelling of 191713421 in words is "one hundred ninety-one million, seven hundred thirteen thousand, four hundred twenty-one".