78000019 has 2 divisors, whose sum is σ = 78000020. Its totient is φ = 78000018.

The previous prime is 78000017. The next prime is 78000023. The reversal of 78000019 is 91000087.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78000019 - 2¹ = 78000017 is a prime.

It is a super-2 number, since 2×78000019² = 12168005928000722, which contains 22 as substring.

Together with 78000017, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 77999957 and 78000002.

It is not a weakly prime, because it can be changed into another prime (78000011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39000009 + 39000010.

It is an arithmetic number, because the mean of its divisors is an integer number (39000010).

Almost surely, 2^78000019 is an apocalyptic number.

78000019 is a deficient number, since it is larger than the sum of its proper divisors (1).

78000019 is an equidigital number, since it uses as much as digits as its factorization.

78000019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 25.

The square root of 78000019 is about 8831.7619419910. The cubic root of 78000019 is about 427.2659028623.

The spelling of 78000019 in words is "seventy-eight million, nineteen", and thus it is an aban number and an uban number.