20898090 has 48 divisors (see below), whose sum is σ = 54966600. Its totient is φ = 5508096.

The previous prime is 20898047. The next prime is 20898091. The reversal of 20898090 is 9089802.

It can be written as a sum of positive squares in 4 ways, for example, as 13461561 + 7436529 = 3669^2 + 2727^2 .

It is not an unprimeable number, because it can be changed into a prime (20898091) 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, 6706 + ... + 9314.

Almost surely, 2^20898090 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20898090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27483300).

20898090 is an abundant number, since it is smaller than the sum of its proper divisors (34068510).

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

20898090 is a wasteful number, since it uses less digits than its factorization.

20898090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2711 (or 2708 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 20898090 is about 4571.4428794419. The cubic root of 20898090 is about 275.4454049303.

The spelling of 20898090 in words is "twenty million, eight hundred ninety-eight thousand, ninety".