376521806821 has 2 divisors, whose sum is σ = 376521806822. Its totient is φ = 376521806820.

The previous prime is 376521806783. The next prime is 376521806923. The reversal of 376521806821 is 128608125673.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 360673514721 + 15848292100 = 600561^2 + 125890^2 .

It is a cyclic number.

It is not a de Polignac number, because 376521806821 - 2²¹ = 376519709669 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (376521807821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 188260903410 + 188260903411.

It is an arithmetic number, because the mean of its divisors is an integer number (188260903411).

Almost surely, 2^376521806821 is an apocalyptic number.

It is an amenable number.

376521806821 is a deficient number, since it is larger than the sum of its proper divisors (1).

376521806821 is an equidigital number, since it uses as much as digits as its factorization.

376521806821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 967680, while the sum is 49.

The spelling of 376521806821 in words is "three hundred seventy-six billion, five hundred twenty-one million, eight hundred six thousand, eight hundred twenty-one".