84390400 has 120 divisors (see below), whose sum is σ = 220722480. Its totient is φ = 31887360.

The previous prime is 84390391. The next prime is 84390403. The reversal of 84390400 is 409348.

It is a super-2 number, since 2×84390400² = 14243479224320000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (84390403) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 243027 + ... + 243373.

It is an arithmetic number, because the mean of its divisors is an integer number (1839354).

Almost surely, 2^84390400 is an apocalyptic number.

84390400 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 84390400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110361240).

84390400 is an abundant number, since it is smaller than the sum of its proper divisors (136332080).

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

84390400 is a wasteful number, since it uses less digits than its factorization.

84390400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 394 (or 373 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 84390400 is about 9186.4247670136. The cubic root of 84390400 is about 438.6293434779.

Adding to 84390400 its reverse (409348), we get a palindrome (84799748).

The spelling of 84390400 in words is "eighty-four million, three hundred ninety thousand, four hundred".