78500000 has 84 divisors (see below), whose sum is σ = 194411574. Its totient is φ = 31200000.

The previous prime is 78499997. The next prime is 78500003. The reversal of 78500000 is 587.

It is an interprime number because it is at equal distance from previous prime (78499997) and next prime (78500003).

It can be written as a sum of positive squares in 7 ways, for example, as 50069776 + 28430224 = 7076^2 + 5332^2 .

It is a sliding number, since 78500000 = 16000000 + 62500000 and 1/16000000 + 1/62500000 = 0.000000078500000.

It is a hoax number, since the sum of its digits (20) 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 (20).

It is not an unprimeable number, because it can be changed into a prime (78500003) 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 13 ways as a sum of consecutive naturals, for example, 499922 + ... + 500078.

Almost surely, 2^78500000 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 78500000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97205787).

78500000 is an abundant number, since it is smaller than the sum of its proper divisors (115911574).

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

78500000 is an frugal number, since it uses more digits than its factorization.

78500000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197 (or 164 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 78500000 is about 8860.0225733347. The cubic root of 78500000 is about 428.1768855723.

Adding to 78500000 its reverse (587), we get a palindrome (78500587).

The spelling of 78500000 in words is "seventy-eight million, five hundred thousand".