8521438464 has 504 divisors, whose sum is σ = 31849215552. Its totient is φ = 2209628160.

The previous prime is 8521438433. The next prime is 8521438477. The reversal of 8521438464 is 4648341258.

8521438464 is a `hidden beast` number, since 8 + 521 + 43 + 84 + 6 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (504).

It is a super-2 number, since 2×8521438464² (a number of 21 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 55 ways as a sum of consecutive naturals, for example, 14369752 + ... + 14370344.

It is an arithmetic number, because the mean of its divisors is an integer number (63192888).

Almost surely, 2^8521438464 is an apocalyptic number.

8521438464 is a gapful number since it is divisible by the number (84) 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 8521438464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15924607776).

8521438464 is an abundant number, since it is smaller than the sum of its proper divisors (23327777088).

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

8521438464 is an equidigital number, since it uses as much as digits as its factorization.

8521438464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645 (or 616 counting only the distinct ones).

The product of its digits is 737280, while the sum is 45.

The square root of 8521438464 is about 92311.6377495276. The cubic root of 8521438464 is about 2042.5418833470.

It can be divided in two parts, 8521 and 438464, that added together give a triangular number (446985 = T₉₄₅).

The spelling of 8521438464 in words is "eight billion, five hundred twenty-one million, four hundred thirty-eight thousand, four hundred sixty-four".