20216988 has 72 divisors (see below), whose sum is σ = 58705920. Its totient is φ = 5801760.

The previous prime is 20216981. The next prime is 20217019. The reversal of 20216988 is 88961202.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20216981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6181 + ... + 8867.

It is an arithmetic number, because the mean of its divisors is an integer number (815360).

Almost surely, 2^20216988 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 20216988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29352960).

20216988 is an abundant number, since it is smaller than the sum of its proper divisors (38488932).

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

20216988 is a wasteful number, since it uses less digits than its factorization.

20216988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2727 (or 2722 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 20216988 is about 4496.3305038665. The cubic root of 20216988 is about 272.4198928462.

It can be divided in two parts, 2021 and 6988, that added together give a palindrome (9009).

The spelling of 20216988 in words is "twenty million, two hundred sixteen thousand, nine hundred eighty-eight".