78653440 has 48 divisors (see below), whose sum is σ = 188746740. Its totient is φ = 31457280.

The previous prime is 78653437. The next prime is 78653459. The reversal of 78653440 is 4435687.

It can be written as a sum of positive squares in 2 ways, for example, as 78570496 + 82944 = 8864^2 + 288^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 78653440.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6400 + ... + 14080.

Almost surely, 2^78653440 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 78653440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94373370).

78653440 is an abundant number, since it is smaller than the sum of its proper divisors (110093300).

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

78653440 is an equidigital number, since it uses as much as digits as its factorization.

78653440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7708 (or 7688 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 37.

The square root of 78653440 is about 8868.6774662291. The cubic root of 78653440 is about 428.4556826053.

The spelling of 78653440 in words is "seventy-eight million, six hundred fifty-three thousand, four hundred forty".