68648639 has 4 divisors (see below), whose sum is σ = 68974200. Its totient is φ = 68323080.

The previous prime is 68648617. The next prime is 68648651. The reversal of 68648639 is 93684686.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93684686 = 2 ⋅46842343.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68648639 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68698639) 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, 162464 + ... + 162885.

It is an arithmetic number, because the mean of its divisors is an integer number (17243550).

Almost surely, 2^68648639 is an apocalyptic number.

68648639 is a deficient number, since it is larger than the sum of its proper divisors (325561).

68648639 is a wasteful number, since it uses less digits than its factorization.

68648639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 325560.

The product of its digits is 1492992, while the sum is 50.

The square root of 68648639 is about 8285.4474230424. The cubic root of 68648639 is about 409.4592096758.

The spelling of 68648639 in words is "sixty-eight million, six hundred forty-eight thousand, six hundred thirty-nine".