181866370645 has 16 divisors (see below), whose sum is σ = 218439411840. Its totient is φ = 145359998784.

The previous prime is 181866370619. The next prime is 181866370711. The reversal of 181866370645 is 546073668181.

It is a cyclic number.

It is not a de Polignac number, because 181866370645 - 2³⁵ = 147506632277 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48900096 + ... + 48903814.

It is an arithmetic number, because the mean of its divisors is an integer number (13652463240).

Almost surely, 2^181866370645 is an apocalyptic number.

It is an amenable number.

181866370645 is a deficient number, since it is larger than the sum of its proper divisors (36573041195).

181866370645 is a wasteful number, since it uses less digits than its factorization.

181866370645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10044.

The product of its (nonzero) digits is 5806080, while the sum is 55.

The spelling of 181866370645 in words is "one hundred eighty-one billion, eight hundred sixty-six million, three hundred seventy thousand, six hundred forty-five".