168935441781 has 4 divisors (see below), whose sum is σ = 225247255712. Its totient is φ = 112623627852.

The previous prime is 168935441723. The next prime is 168935441803. The reversal of 168935441781 is 187144539861.

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.

It is not a de Polignac number, because 168935441781 - 2²⁹ = 168398570869 is a prime.

It is a super-2 number, since 2×168935441781² (a number of 23 digits) 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 (168935441881) 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, 28155906961 + ... + 28155906966.

It is an arithmetic number, because the mean of its divisors is an integer number (56311813928).

Almost surely, 2^168935441781 is an apocalyptic number.

It is an amenable number.

168935441781 is a deficient number, since it is larger than the sum of its proper divisors (56311813931).

168935441781 is an equidigital number, since it uses as much as digits as its factorization.

168935441781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56311813930.

The product of its digits is 5806080, while the sum is 57.

The spelling of 168935441781 in words is "one hundred sixty-eight billion, nine hundred thirty-five million, four hundred forty-one thousand, seven hundred eighty-one".