20026561091 has 2 divisors, whose sum is σ = 20026561092. Its totient is φ = 20026561090.

The previous prime is 20026561033. The next prime is 20026561103. The reversal of 20026561091 is 19016562002.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20026561091 - 2¹⁰ = 20026560067 is a prime.

It is a super-2 number, since 2×20026561091² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20026561991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10013280545 + 10013280546.

It is an arithmetic number, because the mean of its divisors is an integer number (10013280546).

Almost surely, 2^20026561091 is an apocalyptic number.

20026561091 is a deficient number, since it is larger than the sum of its proper divisors (1).

20026561091 is an equidigital number, since it uses as much as digits as its factorization.

20026561091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 32.

The spelling of 20026561091 in words is "twenty billion, twenty-six million, five hundred sixty-one thousand, ninety-one".