9999899578441 has 4 divisors (see below), whose sum is σ = 9999906286612. Its totient is φ = 9999892870272.

The previous prime is 9999899578433. The next prime is 9999899578453. The reversal of 9999899578441 is 1448759989999.

9999899578441 is a nontrivial binomial coefficient, being equal to C(4472114, 2).

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.

It can be written as a sum of positive squares in 2 ways, for example, as 4720933818441 + 5278965760000 = 2172771^2 + 2297600^2 .

It is a 3-Lehmer number, since φ(9999899578441) divides (9999899578441-1)³.

It is a cyclic number.

It is not a de Polignac number, because 9999899578441 - 2³ = 9999899578433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9999899578481) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1 + ... + 4472113.

It is an arithmetic number, because the mean of its divisors is an integer number (2499976571653).

It is a Poulet number, since it divides 2^{9999899578440}-1.

Almost surely, 2^{9999899578441} is an apocalyptic number.

9999899578441 is the 4472113-rd triangular number and also the 2236057-th hexagonal number.

9999899578441 is the 1490705-th centered nonagonal number.

It is an amenable number.

9999899578441 is a deficient number, since it is larger than the sum of its proper divisors (6708171).

9999899578441 is a wasteful number, since it uses less digits than its factorization.

9999899578441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6708170.

The product of its digits is 19046845440, while the sum is 91.

The spelling of 9999899578441 in words is "nine trillion, nine hundred ninety-nine billion, eight hundred ninety-nine million, five hundred seventy-eight thousand, four hundred forty-one".