68866561 has 8 divisors (see below), whose sum is σ = 71358120. Its totient is φ = 66382848.

The previous prime is 68866559. The next prime is 68866571. The reversal of 68866561 is 16566886.

It can be written as a sum of positive squares in 4 ways, for example, as 38130625 + 30735936 = 6175^2 + 5544^2 .

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

It is a 2-Lehmer number, since φ(68866561) divides (68866561-1)².

It is a cyclic number.

It is not a de Polignac number, because 68866561 - 2¹ = 68866559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68866571) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20385 + ... + 23521.

It is an arithmetic number, because the mean of its divisors is an integer number (8919765).

Almost surely, 2^68866561 is an apocalyptic number.

It is an amenable number.

68866561 is a deficient number, since it is larger than the sum of its proper divisors (2491559).

68866561 is a wasteful number, since it uses less digits than its factorization.

68866561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3923.

The product of its digits is 414720, while the sum is 46.

The square root of 68866561 is about 8298.5878919247. The cubic root of 68866561 is about 409.8920219321.

The spelling of 68866561 in words is "sixty-eight million, eight hundred sixty-six thousand, five hundred sixty-one".