209200640 has 320 divisors, whose sum is σ = 636387840. Its totient is φ = 64880640.

The previous prime is 209200639. The next prime is 209200661. The reversal of 209200640 is 46002902.

It is a tau number, because it is divible by the number of its divisors (320).

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9095669 + ... + 9095691.

It is an arithmetic number, because the mean of its divisors is an integer number (1988712).

Almost surely, 2^209200640 is an apocalyptic number.

209200640 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 209200640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (318193920).

209200640 is an abundant number, since it is smaller than the sum of its proper divisors (427187200).

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

209200640 is a wasteful number, since it uses less digits than its factorization.

209200640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93 (or 77 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 209200640 is about 14463.7699096743. The cubic root of 209200640 is about 593.6370564119.

The spelling of 209200640 in words is "two hundred nine million, two hundred thousand, six hundred forty".