8521365653820 has 72 divisors (see below), whose sum is σ = 25851847877856. Its totient is φ = 2272038425472.

The previous prime is 8521365653813. The next prime is 8521365653909. The reversal of 8521365653820 is 283565631258.

It is a happy number.

8521365653820 is a `hidden beast` number, since 8 + 5 + 2 + 1 + 36 + 56 + 538 + 20 = 666.

It is a super-2 number, since 2×8521365653820² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2132787 + ... + 4646666.

It is an arithmetic number, because the mean of its divisors is an integer number (359053442748).

Almost surely, 2^{8521365653820} is an apocalyptic number.

It is an amenable number.

8521365653820 is an abundant number, since it is smaller than the sum of its proper divisors (17330482224036).

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

8521365653820 is a wasteful number, since it uses less digits than its factorization.

8521365653820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6786451 (or 6786446 counting only the distinct ones).

The product of its (nonzero) digits is 10368000, while the sum is 54.

The spelling of 8521365653820 in words is "eight trillion, five hundred twenty-one billion, three hundred sixty-five million, six hundred fifty-three thousand, eight hundred twenty".