20769047821 has 2 divisors, whose sum is σ = 20769047822. Its totient is φ = 20769047820.

The previous prime is 20769047809. The next prime is 20769047851. The reversal of 20769047821 is 12874096702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15298226596 + 5470821225 = 123686^2 + 73965^2 .

It is a cyclic number.

It is not a de Polignac number, because 20769047821 - 2²⁷ = 20634830093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20769047851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10384523910 + 10384523911.

It is an arithmetic number, because the mean of its divisors is an integer number (10384523911).

Almost surely, 2^20769047821 is an apocalyptic number.

It is an amenable number.

20769047821 is a deficient number, since it is larger than the sum of its proper divisors (1).

20769047821 is an equidigital number, since it uses as much as digits as its factorization.

20769047821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 338688, while the sum is 46.

The spelling of 20769047821 in words is "twenty billion, seven hundred sixty-nine million, forty-seven thousand, eight hundred twenty-one".