78297239 has 2 divisors, whose sum is σ = 78297240. Its totient is φ = 78297238.

The previous prime is 78297229. The next prime is 78297251. The reversal of 78297239 is 93279287.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78297239 - 2⁸ = 78296983 is a prime.

It is a super-2 number, since 2×78297239² = 12260915270046242, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 78297193 and 78297202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78297229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39148619 + 39148620.

It is an arithmetic number, because the mean of its divisors is an integer number (39148620).

Almost surely, 2^78297239 is an apocalyptic number.

78297239 is a deficient number, since it is larger than the sum of its proper divisors (1).

78297239 is an equidigital number, since it uses as much as digits as its factorization.

78297239 is an evil number, because the sum of its binary digits is even.

The product of its digits is 381024, while the sum is 47.

The square root of 78297239 is about 8848.5727097651. The cubic root of 78297239 is about 427.8079155969.

The spelling of 78297239 in words is "seventy-eight million, two hundred ninety-seven thousand, two hundred thirty-nine".