78391007 has 2 divisors, whose sum is σ = 78391008. Its totient is φ = 78391006.

The previous prime is 78390997. The next prime is 78391009. The reversal of 78391007 is 70019387.

It is a strong prime.

It is an emirp because it is prime and its reverse (70019387) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78391007 - 2¹⁸ = 78128863 is a prime.

It is a super-2 number, since 2×78391007² = 12290299956948098, which contains 22 as substring.

Together with 78391009, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78391009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39195503 + 39195504.

It is an arithmetic number, because the mean of its divisors is an integer number (39195504).

Almost surely, 2^78391007 is an apocalyptic number.

78391007 is a deficient number, since it is larger than the sum of its proper divisors (1).

78391007 is an equidigital number, since it uses as much as digits as its factorization.

78391007 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10584, while the sum is 35.

The square root of 78391007 is about 8853.8696059971. The cubic root of 78391007 is about 427.9786269788.

The spelling of 78391007 in words is "seventy-eight million, three hundred ninety-one thousand, seven".