11111001001001 has 16 divisors (see below), whose sum is σ = 12273921240768. Its totient is φ = 9974088552000.

The previous prime is 11111001000991. The next prime is 11111001001003. The reversal of 11111001001001 is 10010010011111.

It is not a de Polignac number, because 11111001001001 - 2⁴² = 6712954489897 is a prime.

11111001001001 is a modest number, since divided by 1001001 gives 11111 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 11111001001001.

It is not an unprimeable number, because it can be changed into a prime (11111001001003) 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, 12991631 + ... + 13820436.

It is an arithmetic number, because the mean of its divisors is an integer number (767120077548).

Almost surely, 2^{11111001001001} is an apocalyptic number.

11111001001001 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11111001001001 is a deficient number, since it is larger than the sum of its proper divisors (1162920239767).

11111001001001 is a wasteful number, since it uses less digits than its factorization.

11111001001001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26812552.

The product of its (nonzero) digits is 1, while the sum is 8.

Adding to 11111001001001 its reverse (10010010011111), we get a palindrome (21121011012112).

It can be divided in two parts, 1111 and 1001001001, that multiplied together give a palindrome (1112112112111).

The spelling of 11111001001001 in words is "eleven trillion, one hundred eleven billion, one million, one thousand, one".