20398920 has 32 divisors (see below), whose sum is σ = 61197120. Its totient is φ = 5439680.

The previous prime is 20398909. The next prime is 20398921. The reversal of 20398920 is 2989302.

It is a super-2 number, since 2×20398920² = 832231874332800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20398921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84876 + ... + 85115.

It is an arithmetic number, because the mean of its divisors is an integer number (1912410).

Almost surely, 2^20398920 is an apocalyptic number.

20398920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20398920 is an abundant number, since it is smaller than the sum of its proper divisors (40798200).

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

20398920 is a wasteful number, since it uses less digits than its factorization.

20398920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170005 (or 170001 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 20398920 is about 4516.5163566625. The cubic root of 20398920 is about 273.2346196519.

The spelling of 20398920 in words is "twenty million, three hundred ninety-eight thousand, nine hundred twenty".