181137181 has 8 divisors (see below), whose sum is σ = 183121400. Its totient is φ = 179159040.

The previous prime is 181137133. The next prime is 181137211. The reversal of 181137181 is 181731181.

It is the 5495-th star number.

It can be written as a sum of positive squares in 4 ways, for example, as 42133081 + 139004100 = 6491^2 + 11790^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a 7-Lehmer number, since φ(181137181) divides (181137181-1)⁷.

It is a cyclic number.

It is not a de Polignac number, because 181137181 - 2¹³ = 181128989 is a prime.

It is a super-2 number, since 2×181137181² = 65621356681253522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181137101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82741 + ... + 84901.

It is an arithmetic number, because the mean of its divisors is an integer number (22890175).

Almost surely, 2^181137181 is an apocalyptic number.

It is an amenable number.

181137181 is a deficient number, since it is larger than the sum of its proper divisors (1984219).

181137181 is a wasteful number, since it uses less digits than its factorization.

181137181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3039.

The product of its digits is 1344, while the sum is 31.

The square root of 181137181 is about 13458.7213731469. The cubic root of 181137181 is about 565.8081535459.

The spelling of 181137181 in words is "one hundred eighty-one million, one hundred thirty-seven thousand, one hundred eighty-one".