181365256901 has 8 divisors (see below), whose sum is σ = 182319613080. Its totient is φ = 180411052032.

The previous prime is 181365256889. The next prime is 181365256951. The reversal of 181365256901 is 109652563181.

It is a Cunningham number, because it is equal to 425870²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 1 + 181365256900 = 1^2 + 425870^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-181365256901 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 (181365256951) 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, 3006605 + ... + 3066333.

It is an arithmetic number, because the mean of its divisors is an integer number (22789951635).

Almost surely, 2^181365256901 is an apocalyptic number.

It is an amenable number.

181365256901 is a deficient number, since it is larger than the sum of its proper divisors (954356179).

181365256901 is a wasteful number, since it uses less digits than its factorization.

181365256901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75655.

The product of its (nonzero) digits is 388800, while the sum is 47.

The spelling of 181365256901 in words is "one hundred eighty-one billion, three hundred sixty-five million, two hundred fifty-six thousand, nine hundred one".