84172440 has 256 divisors, whose sum is σ = 303575040. Its totient is φ = 18585600.

The previous prime is 84172411. The next prime is 84172469. The reversal of 84172440 is 4427148.

It is an interprime number because it is at equal distance from previous prime (84172411) and next prime (84172469).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 84172398 and 84172407.

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 63 ways as a sum of consecutive naturals, for example, 2715225 + ... + 2715255.

It is an arithmetic number, because the mean of its divisors is an integer number (1185840).

Almost surely, 2^84172440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 84172440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (151787520).

84172440 is an abundant number, since it is smaller than the sum of its proper divisors (219402600).

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

84172440 is a wasteful number, since it uses less digits than its factorization.

84172440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95 (or 69 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 30.

The square root of 84172440 is about 9174.5539401107. The cubic root of 84172440 is about 438.2513933910.

Adding to 84172440 its reverse (4427148), we get a palindrome (88599588).

The spelling of 84172440 in words is "eighty-four million, one hundred seventy-two thousand, four hundred forty".