864778500 has 72 divisors (see below), whose sum is σ = 2728102104. Its totient is φ = 230606400.

The previous prime is 864778489. The next prime is 864778501. The reversal of 864778500 is 5877468.

It can be written as a sum of positive squares in 4 ways, for example, as 153809604 + 710968896 = 12402^2 + 26664^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (864778501) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 91587 + ... + 100586.

It is an arithmetic number, because the mean of its divisors is an integer number (37890307).

Almost surely, 2^864778500 is an apocalyptic number.

It is an amenable number.

864778500 is an abundant number, since it is smaller than the sum of its proper divisors (1863323604).

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

864778500 is a wasteful number, since it uses less digits than its factorization.

864778500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192198 (or 192183 counting only the distinct ones).

The product of its (nonzero) digits is 376320, while the sum is 45.

The square root of 864778500 is about 29407.1164856400. The cubic root of 864778500 is about 952.7266082036.

The spelling of 864778500 in words is "eight hundred sixty-four million, seven hundred seventy-eight thousand, five hundred".