20211101909 has 2 divisors, whose sum is σ = 20211101910. Its totient is φ = 20211101908.

The previous prime is 20211101893. The next prime is 20211101927. The reversal of 20211101909 is 90910111202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10428902884 + 9782199025 = 102122^2 + 98905^2 .

It is a cyclic number.

It is not a de Polignac number, because 20211101909 - 2⁴ = 20211101893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20211101509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105550954 + 10105550955.

It is an arithmetic number, because the mean of its divisors is an integer number (10105550955).

Almost surely, 2^20211101909 is an apocalyptic number.

It is an amenable number.

20211101909 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211101909 is an equidigital number, since it uses as much as digits as its factorization.

20211101909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 26.

The spelling of 20211101909 in words is "twenty billion, two hundred eleven million, one hundred one thousand, nine hundred nine".