78100002 has 18 divisors (see below), whose sum is σ = 169297947. Its totient is φ = 26020836.

The previous prime is 78099991. The next prime is 78100003. The reversal of 78100002 is 20000187.

It can be written as a sum of positive squares in only one way, i.e., 39050001 + 39050001 = 6249^2 + 6249^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=6249.

It is a super-2 number, since 2×78100002² = 12199220624800008, which contains 22 as substring.

It is a hoax number, since the sum of its digits (18) 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 (18).

It is not an unprimeable number, because it can be changed into a prime (78100003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 36453 + ... + 38535.

Almost surely, 2^78100002 is an apocalyptic number.

78100002 is an abundant number, since it is smaller than the sum of its proper divisors (91197945).

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

78100002 is an equidigital number, since it uses as much as digits as its factorization.

78100002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4174 (or 2088 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 78100002 is about 8837.4205512695. The cubic root of 78100002 is about 427.4483860945.

Multiplying 78100002 by its sum of digits (18), we get a square (1405800036 = 37494²).

78100002 divided by its sum of digits (18) gives a square (4338889 = 2083²).

Adding to 78100002 its reverse (20000187), we get a palindrome (98100189).

The spelling of 78100002 in words is "seventy-eight million, one hundred thousand, two".