13779804821 has 2 divisors, whose sum is σ = 13779804822. Its totient is φ = 13779804820.

The previous prime is 13779804817. The next prime is 13779804847. The reversal of 13779804821 is 12840897731.

It is a happy number.

13779804821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8130628900 + 5649175921 = 90170^2 + 75161^2 .

It is an emirp because it is prime and its reverse (12840897731) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13779804821 - 2² = 13779804817 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 13779804821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13779804721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6889902410 + 6889902411.

It is an arithmetic number, because the mean of its divisors is an integer number (6889902411).

Almost surely, 2^13779804821 is an apocalyptic number.

It is an amenable number.

13779804821 is a deficient number, since it is larger than the sum of its proper divisors (1).

13779804821 is an equidigital number, since it uses as much as digits as its factorization.

13779804821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 677376, while the sum is 50.

The spelling of 13779804821 in words is "thirteen billion, seven hundred seventy-nine million, eight hundred four thousand, eight hundred twenty-one".