20010091 has 4 divisors (see below), whose sum is σ = 20498184. Its totient is φ = 19522000.

The previous prime is 20010079. The next prime is 20010127. The reversal of 20010091 is 19001002.

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 20010091 - 2¹³ = 20001899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20010041) 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, 243985 + ... + 244066.

It is an arithmetic number, because the mean of its divisors is an integer number (5124546).

Almost surely, 2^20010091 is an apocalyptic number.

20010091 is a deficient number, since it is larger than the sum of its proper divisors (488093).

20010091 is an equidigital number, since it uses as much as digits as its factorization.

20010091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488092.

The product of its (nonzero) digits is 18, while the sum is 13.

The square root of 20010091 is about 4473.2640208242. The cubic root of 20010091 is about 271.4874059640.

Adding to 20010091 its reverse (19001002), we get a palindrome (39011093).

The spelling of 20010091 in words is "twenty million, ten thousand, ninety-one".