85821408 has 36 divisors (see below), whose sum is σ = 244055448. Its totient is φ = 28607040.

The previous prime is 85821403. The next prime is 85821409. The reversal of 85821408 is 80412858.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×85821408² = 14730628142204928, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85821403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 148708 + ... + 149283.

It is an arithmetic number, because the mean of its divisors is an integer number (6779318).

Almost surely, 2^85821408 is an apocalyptic number.

It is an amenable number.

85821408 is an abundant number, since it is smaller than the sum of its proper divisors (158234040).

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

85821408 is a wasteful number, since it uses less digits than its factorization.

85821408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 298007 (or 297996 counting only the distinct ones).

The product of its (nonzero) digits is 20480, while the sum is 36.

The square root of 85821408 is about 9263.9844559455. The cubic root of 85821408 is about 441.0947395452.

The spelling of 85821408 in words is "eighty-five million, eight hundred twenty-one thousand, four hundred eight".