181957389074 has 4 divisors (see below), whose sum is σ = 272936083614. Its totient is φ = 90978694536.

The previous prime is 181957389071. The next prime is 181957389077. The reversal of 181957389074 is 470983759181.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (181957389071) and next prime (181957389077).

It can be written as a sum of positive squares in only one way, i.e., 106043363449 + 75914025625 = 325643^2 + 275525^2 .

It is a junction number, because it is equal to n+sod(n) for n = 181957388998 and 181957389016.

It is not an unprimeable number, because it can be changed into a prime (181957389071) 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, 45489347267 + ... + 45489347270.

Almost surely, 2^181957389074 is an apocalyptic number.

181957389074 is a deficient number, since it is larger than the sum of its proper divisors (90978694540).

181957389074 is an equidigital number, since it uses as much as digits as its factorization.

181957389074 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90978694539.

The product of its (nonzero) digits is 15240960, while the sum is 62.

The spelling of 181957389074 in words is "one hundred eighty-one billion, nine hundred fifty-seven million, three hundred eighty-nine thousand, seventy-four".