78400000000 has 351 divisors, whose sum is σ = 227972051247. Its totient is φ = 26880000000.

The previous prime is 78399999989. The next prime is 78400000001. The reversal of 78400000000 is 487.

It is a happy number.

The square root of 78400000000 is 280000.

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 55741321216 + 22658678784 = 236096^2 + 150528^2 .

It is a super-2 number, since 2×78400000000² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78400000001) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 11199999997 + ... + 11200000003.

Almost surely, 2^78400000000 is an apocalyptic number.

78400000000 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

78400000000 is the 280000-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78400000000

78400000000 is an abundant number, since it is smaller than the sum of its proper divisors (149572051247).

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

78400000000 is an frugal number, since it uses more digits than its factorization.

78400000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78 (or 14 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 19.

Adding to 78400000000 its reverse (487), we get a palindrome (78400000487).

The spelling of 78400000000 in words is "seventy-eight billion, four hundred million", and thus it is an aban number.