68511643 has 4 divisors (see below), whose sum is σ = 70721728. Its totient is φ = 66301560.

The previous prime is 68511613. The next prime is 68511661. The reversal of 68511643 is 34611586.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34611586 = 2 ⋅17305793.

It is not a de Polignac number, because 68511643 - 2¹³ = 68503451 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 68511599 and 68511608.

It is not an unprimeable number, because it can be changed into a prime (68511613) 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, 1104996 + ... + 1105057.

It is an arithmetic number, because the mean of its divisors is an integer number (17680432).

Almost surely, 2^68511643 is an apocalyptic number.

68511643 is a deficient number, since it is larger than the sum of its proper divisors (2210085).

68511643 is a wasteful number, since it uses less digits than its factorization.

68511643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2210084.

The product of its digits is 17280, while the sum is 34.

The square root of 68511643 is about 8277.1760280907. The cubic root of 68511643 is about 409.1866544815.

The spelling of 68511643 in words is "sixty-eight million, five hundred eleven thousand, six hundred forty-three".