21088716 has 24 divisors (see below), whose sum is σ = 53680704. Its totient is φ = 6390480.

The previous prime is 21088703. The next prime is 21088741. The reversal of 21088716 is 61788012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79750 + ... + 80013.

It is an arithmetic number, because the mean of its divisors is an integer number (2236696).

Almost surely, 2^21088716 is an apocalyptic number.

It is an amenable number.

21088716 is an abundant number, since it is smaller than the sum of its proper divisors (32591988).

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

21088716 is a wasteful number, since it uses less digits than its factorization.

21088716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159781 (or 159779 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 33.

The square root of 21088716 is about 4592.2452025126. The cubic root of 21088716 is about 276.2803808987.

The spelling of 21088716 in words is "twenty-one million, eighty-eight thousand, seven hundred sixteen".