20998908 has 72 divisors (see below), whose sum is σ = 63318528. Its totient is φ = 5737248.

The previous prime is 20998897. The next prime is 20998909. The reversal of 20998908 is 80989902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20998909) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3985 + ... + 7607.

It is an arithmetic number, because the mean of its divisors is an integer number (879424).

Almost surely, 2^20998908 is an apocalyptic number.

20998908 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 20998908, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31659264).

20998908 is an abundant number, since it is smaller than the sum of its proper divisors (42319620).

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

20998908 is a wasteful number, since it uses less digits than its factorization.

20998908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3663 (or 3658 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 20998908 is about 4582.4565464388. The cubic root of 20998908 is about 275.8876354200.

The spelling of 20998908 in words is "twenty million, nine hundred ninety-eight thousand, nine hundred eight".