864778 has 4 divisors (see below), whose sum is σ = 1297170. Its totient is φ = 432388.

The previous prime is 864757. The next prime is 864781. The reversal of 864778 is 877468.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 508369 + 356409 = 713^2 + 597^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 864778.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 216193 + ... + 216196.

2⁸⁶⁴⁷⁷⁸ is an apocalyptic number.

864778 is a deficient number, since it is larger than the sum of its proper divisors (432392).

864778 is a wasteful number, since it uses less digits than its factorization.

864778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432391.

The product of its digits is 75264, while the sum is 40.

The square root of 864778 is about 929.9344062890. The cubic root of 864778 is about 95.2726424587.

The spelling of 864778 in words is "eight hundred sixty-four thousand, seven hundred seventy-eight".