78400500 has 48 divisors (see below), whose sum is σ = 228306624. Its totient is φ = 20906400.

The previous prime is 78400499. The next prime is 78400501. The reversal of 78400500 is 500487.

It is an interprime number because it is at equal distance from previous prime (78400499) and next prime (78400501).

It is a super-2 number, since 2×78400500² = 12293276800500000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78400501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24634 + ... + 27633.

It is an arithmetic number, because the mean of its divisors is an integer number (4756388).

Almost surely, 2^78400500 is an apocalyptic number.

It is an amenable number.

78400500 is an abundant number, since it is smaller than the sum of its proper divisors (149906124).

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

78400500 is a wasteful number, since it uses less digits than its factorization.

78400500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52289 (or 52277 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 24.

The square root of 78400500 is about 8854.4056830484. The cubic root of 78400500 is about 427.9959020774.

Adding to 78400500 its reverse (500487), we get a palindrome (78900987).

The spelling of 78400500 in words is "seventy-eight million, four hundred thousand, five hundred".