78844821 has 16 divisors (see below), whose sum is σ = 114877440. Its totient is φ = 47703920.

The previous prime is 78844807. The next prime is 78844841. The reversal of 78844821 is 12844887.

It is not a de Polignac number, because 78844821 - 2⁵ = 78844789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78844841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22066 + ... + 25388.

It is an arithmetic number, because the mean of its divisors is an integer number (7179840).

Almost surely, 2^78844821 is an apocalyptic number.

It is an amenable number.

78844821 is a deficient number, since it is larger than the sum of its proper divisors (36032619).

78844821 is a wasteful number, since it uses less digits than its factorization.

78844821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4056.

The product of its digits is 114688, while the sum is 42.

The square root of 78844821 is about 8879.4606255110. The cubic root of 78844821 is about 428.8029098856.

The spelling of 78844821 in words is "seventy-eight million, eight hundred forty-four thousand, eight hundred twenty-one".