9943723865 has 16 divisors (see below), whose sum is σ = 11997208080. Its totient is φ = 7911905280.

The previous prime is 9943723831. The next prime is 9943723873. The reversal of 9943723865 is 5683273499.

It can be written as a sum of positive squares in 8 ways, for example, as 3723562441 + 6220161424 = 61021^2 + 78868^2 .

It is not a de Polignac number, because 9943723865 - 2¹⁴ = 9943707481 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 9943723865.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1027871 + ... + 1037499.

It is an arithmetic number, because the mean of its divisors is an integer number (749825505).

Almost surely, 2^9943723865 is an apocalyptic number.

It is an amenable number.

9943723865 is a deficient number, since it is larger than the sum of its proper divisors (2053484215).

9943723865 is a wasteful number, since it uses less digits than its factorization.

9943723865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10732.

The product of its digits is 9797760, while the sum is 56.

The square root of 9943723865 is about 99718.2223317283. Note that the first 3 decimals coincide. The cubic root of 9943723865 is about 2150.3856431004.

The spelling of 9943723865 in words is "nine billion, nine hundred forty-three million, seven hundred twenty-three thousand, eight hundred sixty-five".