78278400 has 270 divisors, whose sum is σ = 291347672. Its totient is φ = 20736000.

The previous prime is 78278399. The next prime is 78278401. The reversal of 78278400 is 487287.

It is an interprime number because it is at equal distance from previous prime (78278399) and next prime (78278401).

It is a tau number, because it is divible by the number of its divisors (270).

It is a super-2 number, since 2×78278400² = 12255015813120000, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78278401) by changing a digit.

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 29 ways as a sum of consecutive naturals, for example, 518325 + ... + 518475.

Almost surely, 2^78278400 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 78278400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145673836).

78278400 is an abundant number, since it is smaller than the sum of its proper divisors (213069272).

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

78278400 is a wasteful number, since it uses less digits than its factorization.

78278400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 36.

The square root of 78278400 is about 8847.5081237600. The cubic root of 78278400 is about 427.7736014035.

The spelling of 78278400 in words is "seventy-eight million, two hundred seventy-eight thousand, four hundred".