853866840 has 128 divisors (see below), whose sum is σ = 2705472000. Its totient is φ = 214990848.

The previous prime is 853866809. The next prime is 853866851. The reversal of 853866840 is 48668358.

It is a Cunningham number, because it is equal to 29221²-1.

It is a self number, because there is not a number n which added to its sum of digits gives 853866840.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1109976 + ... + 1110744.

It is an arithmetic number, because the mean of its divisors is an integer number (21136500).

Almost surely, 2^853866840 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 853866840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1352736000).

853866840 is an abundant number, since it is smaller than the sum of its proper divisors (1851605160).

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

853866840 is a wasteful number, since it uses less digits than its factorization.

853866840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1289 (or 1285 counting only the distinct ones).

The product of its (nonzero) digits is 1105920, while the sum is 48.

The square root of 853866840 is about 29220.9999828890. Note that the first 4 decimals coincide. The cubic root of 853866840 is about 948.7025094224.

The spelling of 853866840 in words is "eight hundred fifty-three million, eight hundred sixty-six thousand, eight hundred forty".