8727791521 has 4 divisors (see below), whose sum is σ = 8729564292. Its totient is φ = 8726018752.

The previous prime is 8727791519. The next prime is 8727791537. The reversal of 8727791521 is 1251977278.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4338066496 + 4389725025 = 65864^2 + 66255^2 .

It is a cyclic number.

It is not a de Polignac number, because 8727791521 - 2¹ = 8727791519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8727791561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 878980 + ... + 888853.

It is an arithmetic number, because the mean of its divisors is an integer number (2182391073).

Almost surely, 2^8727791521 is an apocalyptic number.

It is an amenable number.

8727791521 is a deficient number, since it is larger than the sum of its proper divisors (1772771).

8727791521 is a wasteful number, since it uses less digits than its factorization.

8727791521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1772770.

The product of its digits is 493920, while the sum is 49.

The square root of 8727791521 is about 93422.6499356553. The cubic root of 8727791521 is about 2058.8977923220.

The spelling of 8727791521 in words is "eight billion, seven hundred twenty-seven million, seven hundred ninety-one thousand, five hundred twenty-one".