21347859808 has 96 divisors (see below), whose sum is σ = 48184899840. Its totient is φ = 9221506560.

The previous prime is 21347859761. The next prime is 21347859817. The reversal of 21347859808 is 80895874312.

It is a super-2 number, since 2×21347859808² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 540973 + ... + 579091.

It is an arithmetic number, because the mean of its divisors is an integer number (501926040).

Almost surely, 2^21347859808 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21347859808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24092449920).

21347859808 is an abundant number, since it is smaller than the sum of its proper divisors (26837040032).

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

21347859808 is a wasteful number, since it uses less digits than its factorization.

21347859808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38220 (or 38212 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 55.

The spelling of 21347859808 in words is "twenty-one billion, three hundred forty-seven million, eight hundred fifty-nine thousand, eight hundred eight".