999999645718441 has 9 divisors (see below), whose sum is σ = 1062283931747031. Its totient is φ = 941175631182432.

The previous prime is 999999645718387. The next prime is 999999645718481. The reversal of 999999645718441 is 144817546999999.

The square root of 999999645718441 is 31622771.

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., 778546436978025 + 221453208740416 = 27902445^2 + 14881304^2 .

It is not a de Polignac number, because 999999645718441 - 2⁹ = 999999645717929 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 999999645718441.

It is not an unprimeable number, because it can be changed into a prime (999999645718481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 536657026 + ... + 538517188.

Almost surely, 2^{999999645718441} is an apocalyptic number.

999999645718441 is the 31622771-st square number.

999999645718441 is the 15811386-th centered octagonal number.

It is an amenable number.

999999645718441 is a deficient number, since it is larger than the sum of its proper divisors (62284286028590).

999999645718441 is an frugal number, since it uses more digits than its factorization.

999999645718441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3720360 (or 1860180 counting only the distinct ones).

The product of its digits is 57140536320, while the sum is 94.

The spelling of 999999645718441 in words is "nine hundred ninety-nine trillion, nine hundred ninety-nine billion, six hundred forty-five million, seven hundred eighteen thousand, four hundred forty-one".