11111101001001 has 6 divisors (see below), whose sum is σ = 16049368112570. Its totient is φ = 7407400667328.

The previous prime is 11111101000969. The next prime is 11111101001009. The reversal of 11111101001001 is 10010010111111.

It can be written as a sum of positive squares in only one way, i.e., 9104557925376 + 2006543075625 = 3017376^2 + 1416525^2 .

It is not a de Polignac number, because 11111101001001 - 2⁵ = 11111101000969 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 1234566777889 = 11111101001001 / (1 + 1 + 1 + 1 + 1 + 1 + 0 + 1 + 0 + 0 + 1 + 0 + 0 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11111101001009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 617283388936 + ... + 617283388953.

Almost surely, 2^{11111101001001} is an apocalyptic number.

It is an amenable number.

11111101001001 is a deficient number, since it is larger than the sum of its proper divisors (4938267111569).

11111101001001 is a wasteful number, since it uses less digits than its factorization.

11111101001001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1234566777895 (or 1234566777892 counting only the distinct ones).

The product of its (nonzero) digits is 1, while the sum is 9.

Adding to 11111101001001 its reverse (10010010111111), we get a palindrome (21121111112112).

The spelling of 11111101001001 in words is "eleven trillion, one hundred eleven billion, one hundred one million, one thousand, one".