181869494 has 4 divisors (see below), whose sum is σ = 272804244. Its totient is φ = 90934746.

The previous prime is 181869491. The next prime is 181869511. The reversal of 181869494 is 494968181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 494968181 = 9397 ⋅52673.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181869491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45467372 + ... + 45467375.

It is an arithmetic number, because the mean of its divisors is an integer number (68201061).

Almost surely, 2^181869494 is an apocalyptic number.

181869494 is a deficient number, since it is larger than the sum of its proper divisors (90934750).

181869494 is an equidigital number, since it uses as much as digits as its factorization.

181869494 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90934749.

The product of its digits is 497664, while the sum is 50.

The square root of 181869494 is about 13485.8998216656. The cubic root of 181869494 is about 566.5696234435.

The spelling of 181869494 in words is "one hundred eighty-one million, eight hundred sixty-nine thousand, four hundred ninety-four".