68020081 has 4 divisors (see below), whose sum is σ = 68302564. Its totient is φ = 67737600.

The previous prime is 68020079. The next prime is 68020087. The reversal of 68020081 is 18002086.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21902400 + 46117681 = 4680^2 + 6791^2 .

It is a cyclic number.

It is not a de Polignac number, because 68020081 - 2¹ = 68020079 is a prime.

It is a super-2 number, since 2×68020081² = 9253462838493122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68020087) 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, 140880 + ... + 141361.

It is an arithmetic number, because the mean of its divisors is an integer number (17075641).

Almost surely, 2^68020081 is an apocalyptic number.

It is an amenable number.

68020081 is a deficient number, since it is larger than the sum of its proper divisors (282483).

68020081 is a wasteful number, since it uses less digits than its factorization.

68020081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282482.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 68020081 is about 8247.4287508290. The cubic root of 68020081 is about 408.2056845296.

The spelling of 68020081 in words is "sixty-eight million, twenty thousand, eighty-one".