168013781 has 16 divisors (see below), whose sum is σ = 193920384. Its totient is φ = 144327744.

The previous prime is 168013759. The next prime is 168013801. The reversal of 168013781 is 187310861.

It is a cyclic number.

It is not a de Polignac number, because 168013781 - 2¹⁴ = 167997397 is a prime.

It is a super-2 number, since 2×168013781² = 56457261211831922, 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 (168013721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3470 + ... + 18656.

It is an arithmetic number, because the mean of its divisors is an integer number (12120024).

Almost surely, 2^168013781 is an apocalyptic number.

It is an amenable number.

168013781 is a deficient number, since it is larger than the sum of its proper divisors (25906603).

168013781 is a wasteful number, since it uses less digits than its factorization.

168013781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15260.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 168013781 is about 12962.0129995306. The cubic root of 168013781 is about 551.7999224566.

The spelling of 168013781 in words is "one hundred sixty-eight million, thirteen thousand, seven hundred eighty-one".