209473920 has 192 divisors, whose sum is σ = 741817440. Its totient is φ = 54435840.

The previous prime is 209473919. The next prime is 209473921. The reversal of 209473920 is 29374902.

It is an interprime number because it is at equal distance from previous prime (209473919) and next prime (209473921).

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209473921) 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 23 ways as a sum of consecutive naturals, for example, 235717 + ... + 236603.

Almost surely, 2^209473920 is an apocalyptic number.

209473920 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 209473920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (370908720).

209473920 is an abundant number, since it is smaller than the sum of its proper divisors (532343520).

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

209473920 is a wasteful number, since it uses less digits than its factorization.

209473920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 953 (or 938 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

The square root of 209473920 is about 14473.2138794395. The cubic root of 209473920 is about 593.8954344387.

The spelling of 209473920 in words is "two hundred nine million, four hundred seventy-three thousand, nine hundred twenty".