8640019521 has 48 divisors (see below), whose sum is σ = 14948354880. Its totient is φ = 4917749760.

The previous prime is 8640019513. The next prime is 8640019537. The reversal of 8640019521 is 1259100468.

8640019521 is a `hidden beast` number, since 8 + 640 + 0 + 1 + 9 + 5 + 2 + 1 = 666.

It is not a de Polignac number, because 8640019521 - 2³ = 8640019513 is a prime.

It is a super-2 number, since 2×8640019521² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (8640019571) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 327306 + ... + 352716.

It is an arithmetic number, because the mean of its divisors is an integer number (311424060).

Almost surely, 2^8640019521 is an apocalyptic number.

It is an amenable number.

8640019521 is a deficient number, since it is larger than the sum of its proper divisors (6308335359).

8640019521 is a wasteful number, since it uses less digits than its factorization.

8640019521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25691 (or 25678 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 8640019521 is about 92951.7053151797. The cubic root of 8640019521 is about 2051.9726814016.

Adding to 8640019521 its reverse (1259100468), we get a palindrome (9899119989).

The spelling of 8640019521 in words is "eight billion, six hundred forty million, nineteen thousand, five hundred twenty-one".