68440223857 has 8 divisors (see below), whose sum is σ = 72525105000. Its totient is φ = 64361896704.

The previous prime is 68440223843. The next prime is 68440223869. The reversal of 68440223857 is 75832204486.

It can be written as a sum of positive squares in 4 ways, for example, as 44302251361 + 24137972496 = 210481^2 + 155364^2 .

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 68440223857 - 2²³ = 68431835249 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 68440223857.

It is not an unprimeable number, because it can be changed into a prime (68440223807) 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 in 7 ways as a sum of consecutive naturals, for example, 1616982 + ... + 1658767.

It is an arithmetic number, because the mean of its divisors is an integer number (9065638125).

Almost surely, 2^68440223857 is an apocalyptic number.

It is an amenable number.

68440223857 is a deficient number, since it is larger than the sum of its proper divisors (4084881143).

68440223857 is a wasteful number, since it uses less digits than its factorization.

68440223857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3276995.

The product of its (nonzero) digits is 2580480, while the sum is 49.

The spelling of 68440223857 in words is "sixty-eight billion, four hundred forty million, two hundred twenty-three thousand, eight hundred fifty-seven".