21194262711808 has 80 divisors (see below), whose sum is σ = 42425340604416. Its totient is φ = 10577568798720.

The previous prime is 21194262711767. The next prime is 21194262711821. The reversal of 21194262711808 is 80811726249112.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1855396785 + ... + 1855408207.

Almost surely, 2^{21194262711808} 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 21194262711808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21212670302208).

21194262711808 is an abundant number, since it is smaller than the sum of its proper divisors (21231077892608).

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

21194262711808 is an equidigital number, since it uses as much as digits as its factorization.

21194262711808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17815 (or 17799 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 52.

The spelling of 21194262711808 in words is "twenty-one trillion, one hundred ninety-four billion, two hundred sixty-two million, seven hundred eleven thousand, eight hundred eight".