67678639 has 4 divisors (see below), whose sum is σ = 77347024. Its totient is φ = 58010256.

The previous prime is 67678619. The next prime is 67678651. The reversal of 67678639 is 93687676.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-67678639 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 (67678619) 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, 4834182 + ... + 4834195.

It is an arithmetic number, because the mean of its divisors is an integer number (19336756).

Almost surely, 2^67678639 is an apocalyptic number.

67678639 is a deficient number, since it is larger than the sum of its proper divisors (9668385).

67678639 is an equidigital number, since it uses as much as digits as its factorization.

67678639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9668384.

The product of its digits is 2286144, while the sum is 52.

The square root of 67678639 is about 8226.7028024598. The cubic root of 67678639 is about 407.5215119059.

The spelling of 67678639 in words is "sixty-seven million, six hundred seventy-eight thousand, six hundred thirty-nine".