8161681328 has 10 divisors (see below), whose sum is σ = 15813257604. Its totient is φ = 4080840656.

The previous prime is 8161681327. The next prime is 8161681337. The reversal of 8161681328 is 8231861618.

It is a happy number.

It is a super-2 number, since 2×8161681328² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (8161681321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 255052526 + ... + 255052557.

Almost surely, 2^8161681328 is an apocalyptic number.

It is an amenable number.

8161681328 is a deficient number, since it is larger than the sum of its proper divisors (7651576276).

8161681328 is a wasteful number, since it uses less digits than its factorization.

8161681328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510105091 (or 510105085 counting only the distinct ones).

The product of its digits is 110592, while the sum is 44.

The square root of 8161681328 is about 90342.0241526611. The cubic root of 8161681328 is about 2013.3836827411.

The spelling of 8161681328 in words is "eight billion, one hundred sixty-one million, six hundred eighty-one thousand, three hundred twenty-eight".