181081957 has 4 divisors (see below), whose sum is σ = 206950816. Its totient is φ = 155213100.

The previous prime is 181081933. The next prime is 181081961. The reversal of 181081957 is 759180181.

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, and also an emirpimes, since its reverse is a distinct semiprime: 759180181 = 149 ⋅5095169.

It is not a de Polignac number, because 181081957 - 2²³ = 172693349 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 (181081907) 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, 12934419 + ... + 12934432.

It is an arithmetic number, because the mean of its divisors is an integer number (51737704).

Almost surely, 2^181081957 is an apocalyptic number.

It is an amenable number.

181081957 is a deficient number, since it is larger than the sum of its proper divisors (25868859).

181081957 is an equidigital number, since it uses as much as digits as its factorization.

181081957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25868858.

The product of its (nonzero) digits is 20160, while the sum is 40.

The square root of 181081957 is about 13456.6696102713. The cubic root of 181081957 is about 565.7506476541.

The spelling of 181081957 in words is "one hundred eighty-one million, eighty-one thousand, nine hundred fifty-seven".