20398900 has 18 divisors (see below), whose sum is σ = 44265830. Its totient is φ = 8159520.

The previous prime is 20398897. The next prime is 20398909. The reversal of 20398900 is 989302.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 94864 + 20304036 = 308^2 + 4506^2 .

It is a super-2 number, since 2×20398900² = 832230242420000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20398909) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 101895 + ... + 102094.

Almost surely, 2^20398900 is an apocalyptic number.

20398900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20398900 is an abundant number, since it is smaller than the sum of its proper divisors (23866930).

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

20398900 is a wasteful number, since it uses less digits than its factorization.

20398900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204003 (or 203996 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 20398900 is about 4516.5141425661. The cubic root of 20398900 is about 273.2345303547.

The spelling of 20398900 in words is "twenty million, three hundred ninety-eight thousand, nine hundred".