21165088 has 48 divisors (see below), whose sum is σ = 50137920. Its totient is φ = 8591616.

The previous prime is 21165077. The next prime is 21165097. The reversal of 21165088 is 88056112.

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, 1770 + ... + 6742.

It is an arithmetic number, because the mean of its divisors is an integer number (1044540).

Almost surely, 2^21165088 is an apocalyptic number.

21165088 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21165088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25068960).

21165088 is an abundant number, since it is smaller than the sum of its proper divisors (28972832).

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

21165088 is a wasteful number, since it uses less digits than its factorization.

21165088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5009 (or 5001 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 31.

The square root of 21165088 is about 4600.5530102369. The cubic root of 21165088 is about 276.6134921435.

The spelling of 21165088 in words is "twenty-one million, one hundred sixty-five thousand, eighty-eight".