78400000 has 180 divisors, whose sum is σ = 227762766. Its totient is φ = 26880000.

The previous prime is 78399989. The next prime is 78400019. The reversal of 78400000 is 487.

It is a happy number.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 3 ways, for example, as 112896 + 78287104 = 336^2 + 8848^2 .

It is a super-2 number, since 2×78400000² = 12293120000000000, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 11199997 + ... + 11200003.

Almost surely, 2^78400000 is an apocalyptic number.

78400000 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78400000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113881383).

78400000 is an abundant number, since it is smaller than the sum of its proper divisors (149362766).

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

78400000 is an frugal number, since it uses more digits than its factorization.

78400000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57 (or 14 counting only the distinct ones).

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

The square root of 78400000 is about 8854.3774484715. The cubic root of 78400000 is about 427.9949922260.

Adding to 78400000 its reverse (487), we get a palindrome (78400487).

The spelling of 78400000 in words is "seventy-eight million, four hundred thousand".