78461819 has 4 divisors (see below), whose sum is σ = 78564096. Its totient is φ = 78359544.

The previous prime is 78461813. The next prime is 78461821. The reversal of 78461819 is 91816487.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91816487 = 7 ⋅13116641.

It is a cyclic number.

It is not a de Polignac number, because 78461819 - 2²⁰ = 77413243 is a prime.

It is a super-2 number, since 2×78461819² = 12312514081577522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78461819.

It is not an unprimeable number, because it can be changed into a prime (78461813) 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, 49979 + ... + 51524.

It is an arithmetic number, because the mean of its divisors is an integer number (19641024).

Almost surely, 2^78461819 is an apocalyptic number.

78461819 is a deficient number, since it is larger than the sum of its proper divisors (102277).

78461819 is a wasteful number, since it uses less digits than its factorization.

78461819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102276.

The product of its digits is 96768, while the sum is 44.

The square root of 78461819 is about 8857.8676327884. The cubic root of 78461819 is about 428.1074551142.

The spelling of 78461819 in words is "seventy-eight million, four hundred sixty-one thousand, eight hundred nineteen".