87724788685 has 4 divisors (see below), whose sum is σ = 105269746428. Its totient is φ = 70179830944.

The previous prime is 87724788653. The next prime is 87724788691. The reversal of 87724788685 is 58688742778.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58688742778 = 2 ⋅29344371389.

It can be written as a sum of positive squares in 2 ways, for example, as 15050873124 + 72673915561 = 122682^2 + 269581^2 .

It is a cyclic number.

It is not a de Polignac number, because 87724788685 - 2⁵ = 87724788653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 8772478864 + ... + 8772478873.

It is an arithmetic number, because the mean of its divisors is an integer number (26317436607).

Almost surely, 2^87724788685 is an apocalyptic number.

It is an amenable number.

87724788685 is a deficient number, since it is larger than the sum of its proper divisors (17544957743).

87724788685 is a wasteful number, since it uses less digits than its factorization.

87724788685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17544957742.

The product of its digits is 337182720, while the sum is 70.

The spelling of 87724788685 in words is "eighty-seven billion, seven hundred twenty-four million, seven hundred eighty-eight thousand, six hundred eighty-five".