84209440 has 144 divisors (see below), whose sum is σ = 242004672. Its totient is φ = 27557376.

The previous prime is 84209431. The next prime is 84209443. The reversal of 84209440 is 4490248.

It is a super-2 number, since 2×84209440² = 14182459570227200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (84209443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 180087 + ... + 180553.

It is an arithmetic number, because the mean of its divisors is an integer number (1680588).

Almost surely, 2^84209440 is an apocalyptic number.

84209440 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 84209440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121002336).

84209440 is an abundant number, since it is smaller than the sum of its proper divisors (157795232).

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

84209440 is a wasteful number, since it uses less digits than its factorization.

84209440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 519 (or 504 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 84209440 is about 9176.5701653722. The cubic root of 84209440 is about 438.3155985956.

Adding to 84209440 its reverse (4490248), we get a palindrome (88699688).

The spelling of 84209440 in words is "eighty-four million, two hundred nine thousand, four hundred forty".