20111001091 has 4 divisors (see below), whose sum is σ = 20114030592. Its totient is φ = 20107971592.

The previous prime is 20111001083. The next prime is 20111001107. The reversal of 20111001091 is 19010011102.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20111001091 - 2³ = 20111001083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20111004091) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1504771 + ... + 1518076.

It is an arithmetic number, because the mean of its divisors is an integer number (5028507648).

Almost surely, 2^20111001091 is an apocalyptic number.

20111001091 is a deficient number, since it is larger than the sum of its proper divisors (3029501).

20111001091 is an equidigital number, since it uses as much as digits as its factorization.

20111001091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3029500.

The product of its (nonzero) digits is 18, while the sum is 16.

Adding to 20111001091 its reverse (19010011102), we get a palindrome (39121012193).

The spelling of 20111001091 in words is "twenty billion, one hundred eleven million, one thousand, ninety-one".