866228640 has 48 divisors (see below), whose sum is σ = 2728621728. Its totient is φ = 230994176.

The previous prime is 866228603. The next prime is 866228641. The reversal of 866228640 is 46822668.

It is a tau number, because it is divible by the number of its divisors (48).

It is a junction number, because it is equal to n+sod(n) for n = 866228592 and 866228601.

It is not an unprimeable number, because it can be changed into a prime (866228641) 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 7 ways as a sum of consecutive naturals, for example, 901842 + ... + 902801.

It is an arithmetic number, because the mean of its divisors is an integer number (56846286).

Almost surely, 2^866228640 is an apocalyptic number.

866228640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

866228640 is an abundant number, since it is smaller than the sum of its proper divisors (1862393088).

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

866228640 is a wasteful number, since it uses less digits than its factorization.

866228640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1804661 (or 1804653 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 42.

The square root of 866228640 is about 29431.7624344856. The cubic root of 866228640 is about 953.2588506314.

The spelling of 866228640 in words is "eight hundred sixty-six million, two hundred twenty-eight thousand, six hundred forty".