190805813 has 4 divisors (see below), whose sum is σ = 208151808. Its totient is φ = 173459820.

The previous prime is 190805803. The next prime is 190805821. The reversal of 190805813 is 318508091.

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 a cyclic number.

It is not a de Polignac number, because 190805813 - 2⁸ = 190805557 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 (190805803) 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, 8672981 + ... + 8673002.

It is an arithmetic number, because the mean of its divisors is an integer number (52037952).

Almost surely, 2^190805813 is an apocalyptic number.

It is an amenable number.

190805813 is a deficient number, since it is larger than the sum of its proper divisors (17345995).

190805813 is a wasteful number, since it uses less digits than its factorization.

190805813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17345994.

The product of its (nonzero) digits is 8640, while the sum is 35.

The square root of 190805813 is about 13813.2477354169. The cubic root of 190805813 is about 575.7012872525.

The spelling of 190805813 in words is "one hundred ninety million, eight hundred five thousand, eight hundred thirteen".