209643097680 has 240 divisors, whose sum is σ = 720564309504. Its totient is φ = 54598717440.

The previous prime is 209643097667. The next prime is 209643097687. The reversal of 209643097680 is 86790346902.

It is a happy number.

209643097680 is a `hidden beast` number, since 209 + 64 + 309 + 76 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209643097687) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 16473720 + ... + 16486440.

Almost surely, 2^209643097680 is an apocalyptic number.

209643097680 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 209643097680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (360282154752).

209643097680 is an abundant number, since it is smaller than the sum of its proper divisors (510921211824).

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

209643097680 is a wasteful number, since it uses less digits than its factorization.

209643097680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13274 (or 13265 counting only the distinct ones).

The product of its (nonzero) digits is 3919104, while the sum is 54.

The spelling of 209643097680 in words is "two hundred nine billion, six hundred forty-three million, ninety-seven thousand, six hundred eighty".