855666558 has 64 divisors (see below), whose sum is σ = 2006208000. Its totient is φ = 269583552.

The previous prime is 855666523. The next prime is 855666563.

855666558 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (54).

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, 663178 + ... + 664466.

It is an arithmetic number, because the mean of its divisors is an integer number (31347000).

Almost surely, 2^855666558 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 855666558, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1003104000).

855666558 is an abundant number, since it is smaller than the sum of its proper divisors (1150541442).

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

855666558 is a wasteful number, since it uses less digits than its factorization.

855666558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1966 (or 1960 counting only the distinct ones).

The product of its digits is 8640000, while the sum is 54.

The square root of 855666558 is about 29251.7787151482. The cubic root of 855666558 is about 949.3685769051.

The spelling of 855666558 in words is "eight hundred fifty-five million, six hundred sixty-six thousand, five hundred fifty-eight".