9901808997796 has 9 divisors (see below), whose sum is σ = 17328176759649. Its totient is φ = 4950901352184.

The previous prime is 9901808997793. The next prime is 9901808997859. The reversal of 9901808997796 is 6977998081099.

The square root of 9901808997796 is 3146714.

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., 9880649222500 + 21159775296 = 3143350^2 + 145464^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9901808997793) 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, 5506750 + ... + 7080106.

Almost surely, 2^{9901808997796} is an apocalyptic number.

9901808997796 is the 3146714-th square number.

It is an amenable number.

9901808997796 is a deficient number, since it is larger than the sum of its proper divisors (7426367761853).

9901808997796 is an frugal number, since it uses more digits than its factorization.

9901808997796 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3146718 (or 1573359 counting only the distinct ones).

The product of its (nonzero) digits is 1111065984, while the sum is 82.

The spelling of 9901808997796 in words is "nine trillion, nine hundred one billion, eight hundred eight million, nine hundred ninety-seven thousand, seven hundred ninety-six".