8259689721 has 4 divisors (see below), whose sum is σ = 11012919632. Its totient is φ = 5506459812.

The previous prime is 8259689699. The next prime is 8259689731. The reversal of 8259689721 is 1279869528.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 8259689721 - 2⁶ = 8259689657 is a prime.

It is a super-3 number, since 3×8259689721³ (a number of 31 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8259689731) 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 3 ways as a sum of consecutive naturals, for example, 1376614951 + ... + 1376614956.

It is an arithmetic number, because the mean of its divisors is an integer number (2753229908).

Almost surely, 2^8259689721 is an apocalyptic number.

It is an amenable number.

8259689721 is a deficient number, since it is larger than the sum of its proper divisors (2753229911).

8259689721 is a wasteful number, since it uses less digits than its factorization.

8259689721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2753229910.

The product of its digits is 4354560, while the sum is 57.

The square root of 8259689721 is about 90882.8351285324. The cubic root of 8259689721 is about 2021.4107813735.

The spelling of 8259689721 in words is "eight billion, two hundred fifty-nine million, six hundred eighty-nine thousand, seven hundred twenty-one".