78069839 has 2 divisors, whose sum is σ = 78069840. Its totient is φ = 78069838.

The previous prime is 78069829. The next prime is 78069857. The reversal of 78069839 is 93896087.

It is a weak prime.

It is an emirp because it is prime and its reverse (93896087) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78069839 is a prime.

It is a super-2 number, since 2×78069839² = 12189799522971842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78069829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39034919 + 39034920.

It is an arithmetic number, because the mean of its divisors is an integer number (39034920).

Almost surely, 2^78069839 is an apocalyptic number.

78069839 is a deficient number, since it is larger than the sum of its proper divisors (1).

78069839 is an equidigital number, since it uses as much as digits as its factorization.

78069839 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 653184, while the sum is 50.

The square root of 78069839 is about 8835.7138364707. The cubic root of 78069839 is about 427.3933507317.

The spelling of 78069839 in words is "seventy-eight million, sixty-nine thousand, eight hundred thirty-nine".