8252615721 has 24 divisors (see below), whose sum is σ = 12848704704. Its totient is φ = 4697827680.

The previous prime is 8252615719. The next prime is 8252615729. The reversal of 8252615721 is 1275162528.

It is not a de Polignac number, because 8252615721 - 2¹ = 8252615719 is a prime.

It is a super-4 number, since 4×8252615721⁴ (a number of 41 digits) contains 4444 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 8252615721.

It is not an unprimeable number, because it can be changed into a prime (8252615729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 68070 + ... + 145391.

It is an arithmetic number, because the mean of its divisors is an integer number (535362696).

Almost surely, 2^8252615721 is an apocalyptic number.

It is an amenable number.

8252615721 is a deficient number, since it is larger than the sum of its proper divisors (4596088983).

8252615721 is a wasteful number, since it uses less digits than its factorization.

8252615721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213741 (or 213734 counting only the distinct ones).

The product of its digits is 67200, while the sum is 39.

The square root of 8252615721 is about 90843.9085519772. The cubic root of 8252615721 is about 2020.8335383799.

The spelling of 8252615721 in words is "eight billion, two hundred fifty-two million, six hundred fifteen thousand, seven hundred twenty-one".