21273878458 has 64 divisors (see below), whose sum is σ = 37676482560. Its totient is φ = 8822011968.

The previous prime is 21273878441. The next prime is 21273878467. The reversal of 21273878458 is 85487837212.

It is a junction number, because it is equal to n+sod(n) for n = 21273878399 and 21273878408.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 12745648 + ... + 12747316.

It is an arithmetic number, because the mean of its divisors is an integer number (588695040).

Almost surely, 2^21273878458 is an apocalyptic number.

21273878458 is a deficient number, since it is larger than the sum of its proper divisors (16402604102).

21273878458 is a wasteful number, since it uses less digits than its factorization.

21273878458 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1979.

The product of its digits is 6021120, while the sum is 55.

The spelling of 21273878458 in words is "twenty-one billion, two hundred seventy-three million, eight hundred seventy-eight thousand, four hundred fifty-eight".