864776640 has 448 divisors, whose sum is σ = 3563965440. Its totient is φ = 172523520.

The previous prime is 864776623. The next prime is 864776669. The reversal of 864776640 is 46677468.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (448).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 864776640.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1659580 + ... + 1660100.

It is an arithmetic number, because the mean of its divisors is an integer number (7955280).

Almost surely, 2^864776640 is an apocalyptic number.

864776640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 864776640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1781982720).

864776640 is an abundant number, since it is smaller than the sum of its proper divisors (2699188800).

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

864776640 is a wasteful number, since it uses less digits than its factorization.

864776640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 580 (or 570 counting only the distinct ones).

The product of its (nonzero) digits is 1354752, while the sum is 48.

The square root of 864776640 is about 29407.0848606250. The cubic root of 864776640 is about 952.7259251490.

The spelling of 864776640 in words is "eight hundred sixty-four million, seven hundred seventy-six thousand, six hundred forty".