78319789 has 2 divisors, whose sum is σ = 78319790. Its totient is φ = 78319788.

The previous prime is 78319783. The next prime is 78319793. The reversal of 78319789 is 98791387.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58446025 + 19873764 = 7645^2 + 4458^2 .

It is a cyclic number.

It is not a de Polignac number, because 78319789 - 2¹¹ = 78317741 is a prime.

It is a super-2 number, since 2×78319789² = 12267978698009042, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78319783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39159894 + 39159895.

It is an arithmetic number, because the mean of its divisors is an integer number (39159895).

Almost surely, 2^78319789 is an apocalyptic number.

It is an amenable number.

78319789 is a deficient number, since it is larger than the sum of its proper divisors (1).

78319789 is an equidigital number, since it uses as much as digits as its factorization.

78319789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 762048, while the sum is 52.

The square root of 78319789 is about 8849.8468348328. The cubic root of 78319789 is about 427.8489819343.

The spelling of 78319789 in words is "seventy-eight million, three hundred nineteen thousand, seven hundred eighty-nine".