68644643 has 4 divisors (see below), whose sum is σ = 69185280. Its totient is φ = 68104008.

The previous prime is 68644621. The next prime is 68644661. The reversal of 68644643 is 34644686.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34644686 = 2 ⋅17322343.

It is a cyclic number.

It is not a de Polignac number, because 68644643 - 2⁶ = 68644579 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 68644643.

It is not an unprimeable number, because it can be changed into a prime (68644613) 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, 270128 + ... + 270381.

It is an arithmetic number, because the mean of its divisors is an integer number (17296320).

Almost surely, 2^68644643 is an apocalyptic number.

68644643 is a deficient number, since it is larger than the sum of its proper divisors (540637).

68644643 is a wasteful number, since it uses less digits than its factorization.

68644643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540636.

The product of its digits is 331776, while the sum is 41.

The square root of 68644643 is about 8285.2062738353. The cubic root of 68644643 is about 409.4512647223.

The spelling of 68644643 in words is "sixty-eight million, six hundred forty-four thousand, six hundred forty-three".