209538011340 has 144 divisors (see below), whose sum is σ = 726895391040. Its totient is φ = 47861637120.

The previous prime is 209538011339. The next prime is 209538011399. The reversal of 209538011340 is 43110835902.

209538011340 is a `hidden beast` number, since 2 + 0 + 9 + 538 + 0 + 113 + 4 + 0 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 209538011295 and 209538011304.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1809916 + ... + 1922204.

It is an arithmetic number, because the mean of its divisors is an integer number (5047884660).

Almost surely, 2^209538011340 is an apocalyptic number.

209538011340 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 209538011340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (363447695520).

209538011340 is an abundant number, since it is smaller than the sum of its proper divisors (517357379700).

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

209538011340 is a wasteful number, since it uses less digits than its factorization.

209538011340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113792 (or 113787 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The spelling of 209538011340 in words is "two hundred nine billion, five hundred thirty-eight million, eleven thousand, three hundred forty".