21027858208 has 24 divisors (see below), whose sum is σ = 47312681472. Its totient is φ = 9011939136.

The previous prime is 21027858199. The next prime is 21027858223. The reversal of 21027858208 is 80285872012.

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 3 ways as a sum of consecutive naturals, for example, 46936960 + ... + 46937407.

It is an arithmetic number, because the mean of its divisors is an integer number (1971361728).

Almost surely, 2^21027858208 is an apocalyptic number.

21027858208 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21027858208 is an abundant number, since it is smaller than the sum of its proper divisors (26284823264).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21027858208 is an equidigital number, since it uses as much as digits as its factorization.

21027858208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93874384 (or 93874376 counting only the distinct ones).

The product of its (nonzero) digits is 143360, while the sum is 43.

The spelling of 21027858208 in words is "twenty-one billion, twenty-seven million, eight hundred fifty-eight thousand, two hundred eight".