21550895718 has 64 divisors (see below), whose sum is σ = 49655918592. Its totient is φ = 6171339680.

The previous prime is 21550895701. The next prime is 21550895719. The reversal of 21550895718 is 81759805512.

It is a super-2 number, since 2×21550895718² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21550895719) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 40471 + ... + 211517.

It is an arithmetic number, because the mean of its divisors is an integer number (775873728).

Almost surely, 2^21550895718 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21550895718, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24827959296).

21550895718 is an abundant number, since it is smaller than the sum of its proper divisors (28105022874).

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

21550895718 is a wasteful number, since it uses less digits than its factorization.

21550895718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171169.

The product of its (nonzero) digits is 1008000, while the sum is 51.

The spelling of 21550895718 in words is "twenty-one billion, five hundred fifty million, eight hundred ninety-five thousand, seven hundred eighteen".