78426720 has 144 divisors (see below), whose sum is σ = 270663120. Its totient is φ = 20677632.

The previous prime is 78426713. The next prime is 78426739. The reversal of 78426720 is 2762487.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 153826 + ... + 154334.

It is an arithmetic number, because the mean of its divisors is an integer number (1879605).

Almost surely, 2^78426720 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78426720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135331560).

78426720 is an abundant number, since it is smaller than the sum of its proper divisors (192236400).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78426720 is a wasteful number, since it uses less digits than its factorization.

78426720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 637 (or 626 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 36.

The square root of 78426720 is about 8855.8861781303. The cubic root of 78426720 is about 428.0436092636.

The spelling of 78426720 in words is "seventy-eight million, four hundred twenty-six thousand, seven hundred twenty".