20794100909 has 2 divisors, whose sum is σ = 20794100910. Its totient is φ = 20794100908.

The previous prime is 20794100891. The next prime is 20794100917. The reversal of 20794100909 is 90900149702.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18496816009 + 2297284900 = 136003^2 + 47930^2 .

It is a cyclic number.

It is not a de Polignac number, because 20794100909 - 2²⁸ = 20525665453 is a prime.

It is a super-2 number, since 2×20794100909² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20794100939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10397050454 + 10397050455.

It is an arithmetic number, because the mean of its divisors is an integer number (10397050455).

Almost surely, 2^20794100909 is an apocalyptic number.

It is an amenable number.

20794100909 is a deficient number, since it is larger than the sum of its proper divisors (1).

20794100909 is an equidigital number, since it uses as much as digits as its factorization.

20794100909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40824, while the sum is 41.

The spelling of 20794100909 in words is "twenty billion, seven hundred ninety-four million, one hundred thousand, nine hundred nine".