78355640 has 64 divisors (see below), whose sum is σ = 197566560. Its totient is φ = 27717120.

The previous prime is 78355637. The next prime is 78355663. The reversal of 78355640 is 4655387.

It is a super-2 number, since 2×78355640² = 12279212639619200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78355594 and 78355603.

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, 13874 + ... + 18686.

Almost surely, 2^78355640 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 78355640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98783280).

78355640 is an abundant number, since it is smaller than the sum of its proper divisors (119210920).

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

78355640 is a wasteful number, since it uses less digits than its factorization.

78355640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4872 (or 4868 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 38.

The square root of 78355640 is about 8851.8721183713. The cubic root of 78355640 is about 427.9142548118.

The spelling of 78355640 in words is "seventy-eight million, three hundred fifty-five thousand, six hundred forty".