21181208895 has 96 divisors (see below), whose sum is σ = 45966735360. Its totient is φ = 8765406720.

The previous prime is 21181208833. The next prime is 21181208897. The reversal of 21181208895 is 59880218112.

It is not a de Polignac number, because 21181208895 - 2⁷ = 21181208767 is a prime.

It is a super-2 number, since 2×21181208895² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21181208895.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21181208897) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 815347 + ... + 840923.

It is an arithmetic number, because the mean of its divisors is an integer number (478820160).

Almost surely, 2^21181208895 is an apocalyptic number.

21181208895 is an abundant number, since it is smaller than the sum of its proper divisors (24785526465).

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

21181208895 is a wasteful number, since it uses less digits than its factorization.

21181208895 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25845 (or 25842 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 45.

The spelling of 21181208895 in words is "twenty-one billion, one hundred eighty-one million, two hundred eight thousand, eight hundred ninety-five".