78781440 has 176 divisors, whose sum is σ = 264112128. Its totient is φ = 20004864.

The previous prime is 78781427. The next prime is 78781457. The reversal of 78781440 is 4418787.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 353169 + ... + 353391.

Almost surely, 2^78781440 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 78781440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132056064).

78781440 is an abundant number, since it is smaller than the sum of its proper divisors (185330688).

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

78781440 is a wasteful number, since it uses less digits than its factorization.

78781440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274 (or 256 counting only the distinct ones).

The product of its (nonzero) digits is 50176, while the sum is 39.

The square root of 78781440 is about 8875.8909411957. The cubic root of 78781440 is about 428.6879784601.

The spelling of 78781440 in words is "seventy-eight million, seven hundred eighty-one thousand, four hundred forty".