8281640 has 16 divisors (see below), whose sum is σ = 18633780. Its totient is φ = 3312640.

The previous prime is 8281639. The next prime is 8281643. The reversal of 8281640 is 461828.

It can be written as a sum of positive squares in 2 ways, for example, as 7496644 + 784996 = 2738^2 + 886^2 .

It is a super-2 number, since 2×8281640² = 137171122179200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (8281643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 103481 + ... + 103560.

Almost surely, 2^8281640 is an apocalyptic number.

It is an amenable number.

8281640 is an abundant number, since it is smaller than the sum of its proper divisors (10352140).

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

8281640 is a wasteful number, since it uses less digits than its factorization.

8281640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207052 (or 207048 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 8281640 is about 2877.7838695774. The cubic root of 8281640 is about 202.3199843065.

The spelling of 8281640 in words is "eight million, two hundred eighty-one thousand, six hundred forty".