28131571666 has 32 divisors (see below), whose sum is σ = 47783727360. Its totient is φ = 12309820800.

The previous prime is 28131571631. The next prime is 28131571667. The reversal of 28131571666 is 66617513182.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (28131571667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 159931 + ... + 286078.

It is an arithmetic number, because the mean of its divisors is an integer number (1493241480).

Almost surely, 2^28131571666 is an apocalyptic number.

28131571666 is a deficient number, since it is larger than the sum of its proper divisors (19652155694).

28131571666 is a wasteful number, since it uses less digits than its factorization.

28131571666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446130.

The product of its digits is 362880, while the sum is 46.

The spelling of 28131571666 in words is "twenty-eight billion, one hundred thirty-one million, five hundred seventy-one thousand, six hundred sixty-six".