21165945088 has 72 divisors (see below), whose sum is σ = 43126846560. Its totient is φ = 10364497920.

The previous prime is 21165945061. The next prime is 21165945103. The reversal of 21165945088 is 88054956112.

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, 4241731 + ... + 4246717.

It is an arithmetic number, because the mean of its divisors is an integer number (598983980).

Almost surely, 2^21165945088 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 21165945088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21563423280).

21165945088 is an abundant number, since it is smaller than the sum of its proper divisors (21960901472).

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

21165945088 is an equidigital number, since it uses as much as digits as its factorization.

21165945088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5343 (or 5329 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 49.

The spelling of 21165945088 in words is "twenty-one billion, one hundred sixty-five million, nine hundred forty-five thousand, eighty-eight".