78511440 has 160 divisors (see below), whose sum is σ = 294624000. Its totient is φ = 16883712.

The previous prime is 78511417. The next prime is 78511463. The reversal of 78511440 is 4411587.

It is an interprime number because it is at equal distance from previous prime (78511417) and next prime (78511463).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 78511398 and 78511407.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27186 + ... + 29934.

It is an arithmetic number, because the mean of its divisors is an integer number (1841400).

Almost surely, 2^78511440 is an apocalyptic number.

78511440 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78511440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147312000).

78511440 is an abundant number, since it is smaller than the sum of its proper divisors (216112560).

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

78511440 is a wasteful number, since it uses less digits than its factorization.

78511440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2789 (or 2783 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 30.

The square root of 78511440 is about 8860.6681463646. The cubic root of 78511440 is about 428.1976843224.

The spelling of 78511440 in words is "seventy-eight million, five hundred eleven thousand, four hundred forty".