9815991601 has 16 divisors (see below), whose sum is σ = 11120961600. Its totient is φ = 8600171328.

The previous prime is 9815991599. The next prime is 9815991611. The reversal of 9815991601 is 1061995189.

It is not a de Polignac number, because 9815991601 - 2¹ = 9815991599 is a prime.

It is a super-2 number, since 2×9815991601² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9815991611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 198411 + ... + 242896.

It is an arithmetic number, because the mean of its divisors is an integer number (695060100).

Almost surely, 2^9815991601 is an apocalyptic number.

It is an amenable number.

9815991601 is a deficient number, since it is larger than the sum of its proper divisors (1304969999).

9815991601 is a wasteful number, since it uses less digits than its factorization.

9815991601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441408.

The product of its (nonzero) digits is 174960, while the sum is 49.

The square root of 9815991601 is about 99075.6862252288. The cubic root of 9815991601 is about 2141.1383294413.

The spelling of 9815991601 in words is "nine billion, eight hundred fifteen million, nine hundred ninety-one thousand, six hundred one".