84215540 has 24 divisors (see below), whose sum is σ = 180617472. Its totient is φ = 32969120.

The previous prime is 84215519. The next prime is 84215557. The reversal of 84215540 is 4551248.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 43856 + ... + 45735.

It is an arithmetic number, because the mean of its divisors is an integer number (7525728).

Almost surely, 2^84215540 is an apocalyptic number.

It is an amenable number.

84215540 is an abundant number, since it is smaller than the sum of its proper divisors (96401932).

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

84215540 is a wasteful number, since it uses less digits than its factorization.

84215540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89647 (or 89645 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 29.

The square root of 84215540 is about 9176.9025275416. The cubic root of 84215540 is about 438.3261819720.

Adding to 84215540 its reverse (4551248), we get a palindrome (88766788).

The spelling of 84215540 in words is "eighty-four million, two hundred fifteen thousand, five hundred forty".