268169981 has 2 divisors, whose sum is σ = 268169982. Its totient is φ = 268169980.

The previous prime is 268169977. The next prime is 268170017. The reversal of 268169981 is 189961862.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 141967225 + 126202756 = 11915^2 + 11234^2 .

It is a cyclic number.

It is not a de Polignac number, because 268169981 - 2² = 268169977 is a prime.

It is a super-2 number, since 2×268169981² = 143830277419080722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (268169381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 134084990 + 134084991.

It is an arithmetic number, because the mean of its divisors is an integer number (134084991).

Almost surely, 2^268169981 is an apocalyptic number.

It is an amenable number.

268169981 is a deficient number, since it is larger than the sum of its proper divisors (1).

268169981 is an equidigital number, since it uses as much as digits as its factorization.

268169981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 373248, while the sum is 50.

The square root of 268169981 is about 16375.8963418800. The cubic root of 268169981 is about 644.8668523110.

The spelling of 268169981 in words is "two hundred sixty-eight million, one hundred sixty-nine thousand, nine hundred eighty-one".