938842785721 has 3 divisors (see below), whose sum is σ = 938843754661. Its totient is φ = 938841816782.

The previous prime is 938842785677. The next prime is 938842785731. The reversal of 938842785721 is 127587248839.

The square root of 938842785721 is 968939.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 127587248839 = 1871 ⋅68192009.

It is not a de Polignac number, because 938842785721 - 2¹⁷ = 938842654649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (938842785731) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 484470 + ... + 1453408.

Almost surely, 2^938842785721 is an apocalyptic number.

938842785721 is the 968939-th square number.

938842785721 is the 484470-th centered octagonal number.

It is an amenable number.

938842785721 is a deficient number, since it is larger than the sum of its proper divisors (968940).

938842785721 is an frugal number, since it uses more digits than its factorization.

938842785721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1937878 (or 968939 counting only the distinct ones).

The product of its digits is 54190080, while the sum is 64.

Multiplying 938842785721 by its sum of digits (64), we get a square (60085938286144 = 7751512²).

The spelling of 938842785721 in words is "nine hundred thirty-eight billion, eight hundred forty-two million, seven hundred eighty-five thousand, seven hundred twenty-one".