78819619 has 4 divisors (see below), whose sum is σ = 82968040. Its totient is φ = 74671200.

The previous prime is 78819553. The next prime is 78819649. The reversal of 78819619 is 91691887.

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-78819619 is a prime.

It is a super-2 number, since 2×78819619² = 12425064678610322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78819649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2074182 + ... + 2074219.

It is an arithmetic number, because the mean of its divisors is an integer number (20742010).

Almost surely, 2^78819619 is an apocalyptic number.

78819619 is a deficient number, since it is larger than the sum of its proper divisors (4148421).

78819619 is a wasteful number, since it uses less digits than its factorization.

78819619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4148420.

The product of its digits is 217728, while the sum is 49.

The square root of 78819619 is about 8878.0413943617. The cubic root of 78819619 is about 428.7572174211.

The spelling of 78819619 in words is "seventy-eight million, eight hundred nineteen thousand, six hundred nineteen".