8161689680 has 40 divisors (see below), whose sum is σ = 18980556000. Its totient is φ = 3263879808.

The previous prime is 8161689673. The next prime is 8161689689. The reversal of 8161689680 is 869861618.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×8161689680² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8161689689) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 404471 + ... + 424169.

It is an arithmetic number, because the mean of its divisors is an integer number (474513900).

Almost surely, 2^8161689680 is an apocalyptic number.

8161689680 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8161689680 is an abundant number, since it is smaller than the sum of its proper divisors (10818866320).

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

8161689680 is a wasteful number, since it uses less digits than its factorization.

8161689680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24891 (or 24885 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 53.

The square root of 8161689680 is about 90342.0703769844. The cubic root of 8161689680 is about 2013.3843695185.

The spelling of 8161689680 in words is "eight billion, one hundred sixty-one million, six hundred eighty-nine thousand, six hundred eighty".