21278857873468 has 24 divisors (see below), whose sum is σ = 40104597527568. Its totient is φ = 9820488564096.

The previous prime is 21278857873397. The next prime is 21278857873477. The reversal of 21278857873468 is 86437875887212.

It is a junction number, because it is equal to n+sod(n) for n = 21278857873394 and 21278857873403.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9903721 + ... + 11859232.

It is an arithmetic number, because the mean of its divisors is an integer number (1671024896982).

Almost surely, 2^{21278857873468} is an apocalyptic number.

It is an amenable number.

21278857873468 is a deficient number, since it is larger than the sum of its proper divisors (18825739654100).

21278857873468 is a wasteful number, since it uses less digits than its factorization.

21278857873468 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21781773 (or 21781771 counting only the distinct ones).

The product of its digits is 2023096320, while the sum is 76.

The spelling of 21278857873468 in words is "twenty-one trillion, two hundred seventy-eight billion, eight hundred fifty-seven million, eight hundred seventy-three thousand, four hundred sixty-eight".