8021690864 has 80 divisors (see below), whose sum is σ = 18623450880. Its totient is φ = 3304097280.

The previous prime is 8021690861. The next prime is 8021690867. The reversal of 8021690864 is 4680961208.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (8021690861) and next prime (8021690867).

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8021690861) 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, 24764 + ... + 129060.

It is an arithmetic number, because the mean of its divisors is an integer number (232793136).

Almost surely, 2^8021690864 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 8021690864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9311725440).

8021690864 is an abundant number, since it is smaller than the sum of its proper divisors (10601760016).

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

8021690864 is a wasteful number, since it uses less digits than its factorization.

8021690864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104358 (or 104352 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 44.

The square root of 8021690864 is about 89563.8926353695. The cubic root of 8021690864 is about 2001.8059407981.

The spelling of 8021690864 in words is "eight billion, twenty-one million, six hundred ninety thousand, eight hundred sixty-four".