78684869 has 4 divisors (see below), whose sum is σ = 79680960. Its totient is φ = 77688780.

The previous prime is 78684841. The next prime is 78684877. The reversal of 78684869 is 96848687.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78684869 is a prime.

It is a super-2 number, since 2×78684869² = 12382617219094322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78684839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 497927 + ... + 498084.

It is an arithmetic number, because the mean of its divisors is an integer number (19920240).

Almost surely, 2^78684869 is an apocalyptic number.

78684869 is a gapful number since it is divisible by the number (79) formed by its first and last digit.

It is an amenable number.

78684869 is a deficient number, since it is larger than the sum of its proper divisors (996091).

78684869 is an equidigital number, since it uses as much as digits as its factorization.

78684869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 996090.

The product of its digits is 4644864, while the sum is 56.

The square root of 78684869 is about 8870.4491994487. The cubic root of 78684869 is about 428.5127436418.

The spelling of 78684869 in words is "seventy-eight million, six hundred eighty-four thousand, eight hundred sixty-nine".