78699840 has 112 divisors (see below), whose sum is σ = 253520448. Its totient is φ = 20680704.

The previous prime is 78699839. The next prime is 78699871. The reversal of 78699840 is 4899687.

It is a happy number.

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 15 ways as a sum of consecutive naturals, for example, 69519 + ... + 70641.

Almost surely, 2^78699840 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 78699840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (126760224).

78699840 is an abundant number, since it is smaller than the sum of its proper divisors (174820608).

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

78699840 is a wasteful number, since it uses less digits than its factorization.

78699840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1216 (or 1206 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 51.

The square root of 78699840 is about 8871.2930286402. The cubic root of 78699840 is about 428.5399189532.

The spelling of 78699840 in words is "seventy-eight million, six hundred ninety-nine thousand, eight hundred forty".