21985712 has 60 divisors (see below), whose sum is σ = 51313680. Its totient is φ = 9088128.

The previous prime is 21985703. The next prime is 21985753. The reversal of 21985712 is 21758912.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22253 + ... + 23219.

It is an arithmetic number, because the mean of its divisors is an integer number (855228).

Almost surely, 2^21985712 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 21985712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25656840).

21985712 is an abundant number, since it is smaller than the sum of its proper divisors (29327968).

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

21985712 is a wasteful number, since it uses less digits than its factorization.

21985712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1018 (or 1005 counting only the distinct ones).

The product of its digits is 10080, while the sum is 35.

The square root of 21985712 is about 4688.8924065284. The cubic root of 21985712 is about 280.1432600229.

The spelling of 21985712 in words is "twenty-one million, nine hundred eighty-five thousand, seven hundred twelve".