20969045821 has 2 divisors, whose sum is σ = 20969045822. Its totient is φ = 20969045820.

The previous prime is 20969045771. The next prime is 20969045827. The reversal of 20969045821 is 12854096902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18019035225 + 2950010596 = 134235^2 + 54314^2 .

It is a cyclic number.

It is not a de Polignac number, because 20969045821 - 2⁷ = 20969045693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20969045827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10484522910 + 10484522911.

It is an arithmetic number, because the mean of its divisors is an integer number (10484522911).

Almost surely, 2^20969045821 is an apocalyptic number.

It is an amenable number.

20969045821 is a deficient number, since it is larger than the sum of its proper divisors (1).

20969045821 is an equidigital number, since it uses as much as digits as its factorization.

20969045821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 311040, while the sum is 46.

The spelling of 20969045821 in words is "twenty billion, nine hundred sixty-nine million, forty-five thousand, eight hundred twenty-one".