10991220001 has 16 divisors (see below), whose sum is σ = 11710236096. Its totient is φ = 10280452096.

The previous prime is 10991219999. The next prime is 10991220011. The reversal of 10991220001 is 10002219901.

It is a cyclic number.

It is not a de Polignac number, because 10991220001 - 2¹ = 10991219999 is a prime.

It is a super-2 number, since 2×10991220001² (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 (10991220011) 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, 2037630 + ... + 2043016.

It is an arithmetic number, because the mean of its divisors is an integer number (731889756).

Almost surely, 2^10991220001 is an apocalyptic number.

It is an amenable number.

10991220001 is a deficient number, since it is larger than the sum of its proper divisors (719016095).

10991220001 is a wasteful number, since it uses less digits than its factorization.

10991220001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6128.

The product of its (nonzero) digits is 324, while the sum is 25.

Adding to 10991220001 its reverse (10002219901), we get a palindrome (20993439902).

The spelling of 10991220001 in words is "ten billion, nine hundred ninety-one million, two hundred twenty thousand, one".