868581989640 has 384 divisors, whose sum is σ = 3108863721600. Its totient is φ = 217484144640.

The previous prime is 868581989623. The next prime is 868581989647. The reversal of 868581989640 is 46989185868.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is not an unprimeable number, because it can be changed into a prime (868581989647) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 20848030 + ... + 20889650.

It is an arithmetic number, because the mean of its divisors is an integer number (8095999275).

Almost surely, 2^868581989640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 868581989640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1554431860800).

868581989640 is an abundant number, since it is smaller than the sum of its proper divisors (2240281731960).

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

868581989640 is a wasteful number, since it uses less digits than its factorization.

868581989640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41779 (or 41763 counting only the distinct ones).

The product of its (nonzero) digits is 238878720, while the sum is 72.

The spelling of 868581989640 in words is "eight hundred sixty-eight billion, five hundred eighty-one million, nine hundred eighty-nine thousand, six hundred forty".