20403900 has 180 divisors, whose sum is σ = 72469320. Its totient is φ = 4924800.

The previous prime is 20403899. The next prime is 20403913. The reversal of 20403900 is 930402.

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 88986 + ... + 89214.

Almost surely, 2^20403900 is an apocalyptic number.

20403900 is a gapful number since it is divisible by the number (20) 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 20403900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36234660).

20403900 is an abundant number, since it is smaller than the sum of its proper divisors (52065420).

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

20403900 is a wasteful number, since it uses less digits than its factorization.

20403900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266 (or 250 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 20403900 is about 4517.0676328787. The cubic root of 20403900 is about 273.2568528173.

The spelling of 20403900 in words is "twenty million, four hundred three thousand, nine hundred".