8429840 has 20 divisors (see below), whose sum is σ = 19599564. Its totient is φ = 3371904.

The previous prime is 8429833. The next prime is 8429851. The reversal of 8429840 is 489248.

It can be written as a sum of positive squares in 2 ways, for example, as 1628176 + 6801664 = 1276^2 + 2608^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 8429840.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52607 + ... + 52766.

Almost surely, 2^8429840 is an apocalyptic number.

8429840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8429840 is an abundant number, since it is smaller than the sum of its proper divisors (11169724).

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

8429840 is a wasteful number, since it uses less digits than its factorization.

8429840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105386 (or 105380 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 8429840 is about 2903.4186745972. The cubic root of 8429840 is about 203.5196953653.

The spelling of 8429840 in words is "eight million, four hundred twenty-nine thousand, eight hundred forty".