78765019 has 4 divisors (see below), whose sum is σ = 79385344. Its totient is φ = 78144696.

The previous prime is 78764993. The next prime is 78765031. The reversal of 78765019 is 91056787.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78765019 is a prime.

It is a super-2 number, since 2×78765019² = 12407856436140722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78765319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 309972 + ... + 310225.

It is an arithmetic number, because the mean of its divisors is an integer number (19846336).

Almost surely, 2^78765019 is an apocalyptic number.

78765019 is a deficient number, since it is larger than the sum of its proper divisors (620325).

78765019 is a wasteful number, since it uses less digits than its factorization.

78765019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 620324.

The product of its (nonzero) digits is 105840, while the sum is 43.

The square root of 78765019 is about 8874.9658590893. The cubic root of 78765019 is about 428.6581915186.

The spelling of 78765019 in words is "seventy-eight million, seven hundred sixty-five thousand, nineteen".