385716765721 has 45 divisors (see below), whose sum is σ = 478291716009. Its totient is φ = 310152894912.

The previous prime is 385716765659. The next prime is 385716765727. The reversal of 385716765721 is 127567617583.

The square root of 385716765721 is 621061.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 2 ways, for example, as 119708388121 + 266008377600 = 345989^2 + 515760^2 .

It is not a de Polignac number, because 385716765721 - 2¹¹ = 385716763673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (385716765727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 1256406250 + ... + 1256406556.

Almost surely, 2^385716765721 is an apocalyptic number.

385716765721 is the 621061-st square number.

385716765721 is the 310531-st centered octagonal number.

It is an amenable number.

385716765721 is a deficient number, since it is larger than the sum of its proper divisors (92574950288).

385716765721 is an frugal number, since it uses more digits than its factorization.

385716765721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 696 (or 331 counting only the distinct ones).

The product of its digits is 14817600, while the sum is 58.

The spelling of 385716765721 in words is "three hundred eighty-five billion, seven hundred sixteen million, seven hundred sixty-five thousand, seven hundred twenty-one".