78243278400 has 1323 divisors, whose sum is σ = 345107605059. Its totient is φ = 17400821760.

The previous prime is 78243278381. The next prime is 78243278401. The reversal of 78243278400 is 487234287.

The square root of 78243278400 is 279720.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 7427681856 + 70815596544 = 86184^2 + 266112^2 .

It is a tau number, because it is divible by the number of its divisors (1323).

It is a super-2 number, since 2×78243278400² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (78243278401) 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 188 ways as a sum of consecutive naturals, for example, 2114683182 + ... + 2114683218.

Almost surely, 2^78243278400 is an apocalyptic number.

78243278400 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

78243278400 is the 279720-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78243278400

78243278400 is an abundant number, since it is smaller than the sum of its proper divisors (266864326659).

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

78243278400 is an equidigital number, since it uses as much as digits as its factorization.

78243278400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128 (or 54 counting only the distinct ones).

The product of its (nonzero) digits is 602112, while the sum is 45.

The spelling of 78243278400 in words is "seventy-eight billion, two hundred forty-three million, two hundred seventy-eight thousand, four hundred".