21988068 has 24 divisors (see below), whose sum is σ = 51411360. Its totient is φ = 7314240.

The previous prime is 21988067. The next prime is 21988081. The reversal of 21988068 is 86088912.

It is not an unprimeable number, because it can be changed into a prime (21988067) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5248 + ... + 8456.

It is an arithmetic number, because the mean of its divisors is an integer number (2142140).

Almost surely, 2^21988068 is an apocalyptic number.

It is an amenable number.

21988068 is an abundant number, since it is smaller than the sum of its proper divisors (29423292).

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

21988068 is a wasteful number, since it uses less digits than its factorization.

21988068 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3787 (or 3785 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 42.

The square root of 21988068 is about 4689.1436318373. The cubic root of 21988068 is about 280.1532664298.

The spelling of 21988068 in words is "twenty-one million, nine hundred eighty-eight thousand, sixty-eight".