78356840 has 64 divisors (see below), whose sum is σ = 188352000. Its totient is φ = 29272320.

The previous prime is 78356833. The next prime is 78356857. The reversal of 78356840 is 4865387.

It is a happy number.

It is a super-2 number, since 2×78356840² = 12279588749571200, which contains 22 as substring.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

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, 34871 + ... + 37049.

It is an arithmetic number, because the mean of its divisors is an integer number (2943000).

Almost surely, 2^78356840 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 78356840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94176000).

78356840 is an abundant number, since it is smaller than the sum of its proper divisors (109995160).

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

78356840 is a wasteful number, since it uses less digits than its factorization.

78356840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2250 (or 2246 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 41.

The square root of 78356840 is about 8851.9399003834. The cubic root of 78356840 is about 427.9164392727.

The spelling of 78356840 in words is "seventy-eight million, three hundred fifty-six thousand, eight hundred forty".