78465640 has 64 divisors (see below), whose sum is σ = 194037120. Its totient is φ = 28320000.

The previous prime is 78465637. The next prime is 78465661. The reversal of 78465640 is 4656487.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 78465593 and 78465602.

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, 65850 + ... + 67030.

It is an arithmetic number, because the mean of its divisors is an integer number (3031830).

Almost surely, 2^78465640 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 78465640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97018560).

78465640 is an abundant number, since it is smaller than the sum of its proper divisors (115571480).

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

78465640 is a wasteful number, since it uses less digits than its factorization.

78465640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1354 (or 1350 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 40.

The square root of 78465640 is about 8858.0833141261. The cubic root of 78465640 is about 428.1144044477.

The spelling of 78465640 in words is "seventy-eight million, four hundred sixty-five thousand, six hundred forty".