186991313 has 4 divisors (see below), whose sum is σ = 197990820. Its totient is φ = 175991808.

The previous prime is 186991297. The next prime is 186991319. The reversal of 186991313 is 313199681.

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

It can be written as a sum of positive squares in 2 ways, for example, as 66716224 + 120275089 = 8168^2 + 10967^2 .

It is a cyclic number.

It is not a de Polignac number, because 186991313 - 2⁴ = 186991297 is a prime.

It is a super-2 number, since 2×186991313² = 69931502274927938, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (186991319) 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, 5499728 + ... + 5499761.

It is an arithmetic number, because the mean of its divisors is an integer number (49497705).

Almost surely, 2^186991313 is an apocalyptic number.

It is an amenable number.

186991313 is a deficient number, since it is larger than the sum of its proper divisors (10999507).

186991313 is a wasteful number, since it uses less digits than its factorization.

186991313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10999506.

The product of its digits is 34992, while the sum is 41.

The square root of 186991313 is about 13674.4766993110. The cubic root of 186991313 is about 571.8390513718.

The spelling of 186991313 in words is "one hundred eighty-six million, nine hundred ninety-one thousand, three hundred thirteen".