21420859308 has 144 divisors (see below), whose sum is σ = 53080634880. Its totient is φ = 6718237440.

The previous prime is 21420859289. The next prime is 21420859349. The reversal of 21420859308 is 80395802412.

It is a self number, because there is not a number n which added to its sum of digits gives 21420859308.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 123819910 + ... + 123820082.

It is an arithmetic number, because the mean of its divisors is an integer number (368615520).

Almost surely, 2^21420859308 is an apocalyptic number.

It is an amenable number.

21420859308 is an abundant number, since it is smaller than the sum of its proper divisors (31659775572).

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

21420859308 is a wasteful number, since it uses less digits than its factorization.

21420859308 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408 (or 345 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 42.

The spelling of 21420859308 in words is "twenty-one billion, four hundred twenty million, eight hundred fifty-nine thousand, three hundred eight".