21428427420868 has 24 divisors (see below), whose sum is σ = 40387682444760. Its totient is φ = 9889225843200.

The previous prime is 21428427420791. The next prime is 21428427420889. The reversal of 21428427420868 is 86802472482412.

It can be written as a sum of positive squares in 4 ways, for example, as 3606588406404 + 17821839014464 = 1899102^2 + 4221592^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16397653 + ... + 17656156.

It is an arithmetic number, because the mean of its divisors is an integer number (1682820101865).

Almost surely, 2^{21428427420868} is an apocalyptic number.

It is an amenable number.

21428427420868 is a deficient number, since it is larger than the sum of its proper divisors (18959255023892).

21428427420868 is a wasteful number, since it uses less digits than its factorization.

21428427420868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34065927 (or 34065925 counting only the distinct ones).

The product of its (nonzero) digits is 22020096, while the sum is 58.

The spelling of 21428427420868 in words is "twenty-one trillion, four hundred twenty-eight billion, four hundred twenty-seven million, four hundred twenty thousand, eight hundred sixty-eight".