181697162641 has 4 divisors (see below), whose sum is σ = 181810938292. Its totient is φ = 181583386992.

The previous prime is 181697162627. The next prime is 181697162683. The reversal of 181697162641 is 146261796181.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 146261796181 = 145121 ⋅1007861.

It can be written as a sum of positive squares in 2 ways, for example, as 50319911041 + 131377251600 = 224321^2 + 362460^2 .

It is a cyclic number.

It is not a de Polignac number, because 181697162641 - 2²⁵ = 181663608209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181697162041) 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, 56885430 + ... + 56888623.

It is an arithmetic number, because the mean of its divisors is an integer number (45452734573).

Almost surely, 2^181697162641 is an apocalyptic number.

It is an amenable number.

181697162641 is a deficient number, since it is larger than the sum of its proper divisors (113775651).

181697162641 is a wasteful number, since it uses less digits than its factorization.

181697162641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113775650.

The product of its digits is 870912, while the sum is 52.

The spelling of 181697162641 in words is "one hundred eighty-one billion, six hundred ninety-seven million, one hundred sixty-two thousand, six hundred forty-one".