209179419540 has 192 divisors, whose sum is σ = 723549335040. Its totient is φ = 43970181120.

The previous prime is 209179419539. The next prime is 209179419577. The reversal of 209179419540 is 45914971902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1397530 + ... + 1539950.

It is an arithmetic number, because the mean of its divisors is an integer number (3768486120).

Almost surely, 2^209179419540 is an apocalyptic number.

209179419540 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 209179419540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (361774667520).

209179419540 is an abundant number, since it is smaller than the sum of its proper divisors (514369915500).

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

209179419540 is a wasteful number, since it uses less digits than its factorization.

209179419540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142722 (or 142720 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 51.

The spelling of 209179419540 in words is "two hundred nine billion, one hundred seventy-nine million, four hundred nineteen thousand, five hundred forty".