181995913 has 4 divisors (see below), whose sum is σ = 198541008. Its totient is φ = 165450820.

The previous prime is 181995911. The next prime is 181995949. The reversal of 181995913 is 319599181.

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 181995913 - 2¹ = 181995911 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181995911) 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, 8272531 + ... + 8272552.

It is an arithmetic number, because the mean of its divisors is an integer number (49635252).

Almost surely, 2^181995913 is an apocalyptic number.

It is an amenable number.

181995913 is a deficient number, since it is larger than the sum of its proper divisors (16545095).

181995913 is a wasteful number, since it uses less digits than its factorization.

181995913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16545094.

The product of its digits is 87480, while the sum is 46.

The square root of 181995913 is about 13490.5860880838. The cubic root of 181995913 is about 566.7008687930.

The spelling of 181995913 in words is "one hundred eighty-one million, nine hundred ninety-five thousand, nine hundred thirteen".