20011000091 has 4 divisors (see below), whose sum is σ = 20051756184. Its totient is φ = 19970244000.

The previous prime is 20011000057. The next prime is 20011000099. The reversal of 20011000091 is 19000011002.

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 20011000091 - 2⁶ = 20011000027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20011000099) 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, 20377310 + ... + 20378291.

It is an arithmetic number, because the mean of its divisors is an integer number (5012939046).

Almost surely, 2^20011000091 is an apocalyptic number.

20011000091 is a deficient number, since it is larger than the sum of its proper divisors (40756093).

20011000091 is an equidigital number, since it uses as much as digits as its factorization.

20011000091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40756092.

The product of its (nonzero) digits is 18, while the sum is 14.

Adding to 20011000091 its reverse (19000011002), we get a palindrome (39011011093).

The spelling of 20011000091 in words is "twenty billion, eleven million, ninety-one", and thus it is an aban number and an uban number.