866021398 has 16 divisors (see below), whose sum is σ = 1420243344. Its totient is φ = 392780160.

The previous prime is 866021383. The next prime is 866021399. The reversal of 866021398 is 893120668.

866021398 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866021399) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33015 + ... + 53122.

It is an arithmetic number, because the mean of its divisors is an integer number (88765209).

Almost surely, 2^866021398 is an apocalyptic number.

866021398 is a deficient number, since it is larger than the sum of its proper divisors (554221946).

866021398 is a wasteful number, since it uses less digits than its factorization.

866021398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86607.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 866021398 is about 29428.2415036984. The cubic root of 866021398 is about 953.1828233492.

The spelling of 866021398 in words is "eight hundred sixty-six million, twenty-one thousand, three hundred ninety-eight".