21142847866 has 32 divisors (see below), whose sum is σ = 36391605120. Its totient is φ = 9024613056.

The previous prime is 21142847857. The next prime is 21142847879. The reversal of 21142847866 is 66874824112.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4283536 + ... + 4288468.

It is an arithmetic number, because the mean of its divisors is an integer number (1137237660).

Almost surely, 2^21142847866 is an apocalyptic number.

21142847866 is a deficient number, since it is larger than the sum of its proper divisors (15248757254).

21142847866 is a wasteful number, since it uses less digits than its factorization.

21142847866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6118.

The product of its digits is 1032192, while the sum is 49.

The spelling of 21142847866 in words is "twenty-one billion, one hundred forty-two million, eight hundred forty-seven thousand, eight hundred sixty-six".