84431520 has 144 divisors (see below), whose sum is σ = 305159400. Its totient is φ = 21184512.

The previous prime is 84431483. The next prime is 84431531. The reversal of 84431520 is 2513448.

It can be written as a sum of positive squares in 4 ways, for example, as 51667344 + 32764176 = 7188^2 + 5724^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22756 + ... + 26204.

Almost surely, 2^84431520 is an apocalyptic number.

84431520 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 84431520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (152579700).

84431520 is an abundant number, since it is smaller than the sum of its proper divisors (220727880).

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

84431520 is a wasteful number, since it uses less digits than its factorization.

84431520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3487 (or 3476 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 84431520 is about 9188.6625795052. The cubic root of 84431520 is about 438.7005739730.

Adding to 84431520 its reverse (2513448), we get a palindrome (86944968).

The spelling of 84431520 in words is "eighty-four million, four hundred thirty-one thousand, five hundred twenty".