68353981 has 8 divisors (see below), whose sum is σ = 68912600. Its totient is φ = 67798080.

The previous prime is 68353973. The next prime is 68354021. The reversal of 68353981 is 18935386.

It can be written as a sum of positive squares in 4 ways, for example, as 538756 + 67815225 = 734^2 + 8235^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 68353981 - 2³ = 68353973 is a prime.

It is a super-2 number, since 2×68353981² = 9344533437096722, 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 (68353931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 96055 + ... + 96763.

It is an arithmetic number, because the mean of its divisors is an integer number (8614075).

Almost surely, 2^68353981 is an apocalyptic number.

It is an amenable number.

68353981 is a deficient number, since it is larger than the sum of its proper divisors (558619).

68353981 is a wasteful number, since it uses less digits than its factorization.

68353981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1359.

The product of its digits is 155520, while the sum is 43.

The square root of 68353981 is about 8267.6466421830. The cubic root of 68353981 is about 408.8725339723.

It can be divided in two parts, 6835 and 3981, that added together give a square (10816 = 104²).

The spelling of 68353981 in words is "sixty-eight million, three hundred fifty-three thousand, nine hundred eighty-one".