8209213539840 has 640 divisors, whose sum is σ = 30319903152000. Its totient is φ = 2102806315008.

The previous prime is 8209213539833. The next prime is 8209213539911. The reversal of 8209213539840 is 489353129028.

8209213539840 is a `hidden beast` number, since 8 + 2 + 0 + 9 + 21 + 3 + 539 + 84 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (54).

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, 394872166 + ... + 394892954.

It is an arithmetic number, because the mean of its divisors is an integer number (47374848675).

Almost surely, 2^{8209213539840} is an apocalyptic number.

8209213539840 is a gapful number since it is divisible by the number (80) 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 8209213539840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15159951576000).

8209213539840 is an abundant number, since it is smaller than the sum of its proper divisors (22110689612160).

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

8209213539840 is a wasteful number, since it uses less digits than its factorization.

8209213539840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21047 (or 21025 counting only the distinct ones).

The product of its (nonzero) digits is 3732480, while the sum is 54.

The spelling of 8209213539840 in words is "eight trillion, two hundred nine billion, two hundred thirteen million, five hundred thirty-nine thousand, eight hundred forty".