78638040 has 160 divisors (see below), whose sum is σ = 284795280. Its totient is φ = 19346688.

The previous prime is 78638033. The next prime is 78638047. The reversal of 78638040 is 4083687.

It is an interprime number because it is at equal distance from previous prime (78638033) and next prime (78638047).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 78637986 and 78638004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78638047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 41187 + ... + 43053.

Almost surely, 2^78638040 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 78638040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (142397640).

78638040 is an abundant number, since it is smaller than the sum of its proper divisors (206157240).

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

78638040 is a wasteful number, since it uses less digits than its factorization.

78638040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1903 (or 1890 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 78638040 is about 8867.8091995712. The cubic root of 78638040 is about 428.4277175297.

The spelling of 78638040 in words is "seventy-eight million, six hundred thirty-eight thousand, forty".