983942979721 has 9 divisors (see below), whose sum is σ = 1065467012679. Its totient is φ = 908243154936.

The previous prime is 983942979707. The next prime is 983942979727. The reversal of 983942979721 is 127979249389.

The square root of 983942979721 is 991939.

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

It can be written as a sum of positive squares in only one way, i.e., 145553695225 + 838389284496 = 381515^2 + 915636^2 .

It is a de Polignac number, because none of the positive numbers 2^k-983942979721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (983942979727) 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 8 ways as a sum of consecutive naturals, for example, 12857056 + ... + 12933358.

It is an arithmetic number, because the mean of its divisors is an integer number (118385223631).

Almost surely, 2^983942979721 is an apocalyptic number.

983942979721 is the 991939-th square number.

983942979721 is the 495970-th centered octagonal number.

It is an amenable number.

983942979721 is a deficient number, since it is larger than the sum of its proper divisors (81524032958).

983942979721 is an frugal number, since it uses more digits than its factorization.

983942979721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152632 (or 76316 counting only the distinct ones).

The product of its digits is 123451776, while the sum is 70.

The spelling of 983942979721 in words is "nine hundred eighty-three billion, nine hundred forty-two million, nine hundred seventy-nine thousand, seven hundred twenty-one".