3656820521 has 2 divisors, whose sum is σ = 3656820522. Its totient is φ = 3656820520.

The previous prime is 3656820473. The next prime is 3656820523. The reversal of 3656820521 is 1250286563.

3656820521 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3441464896 + 215355625 = 58664^2 + 14675^2 .

It is an emirp because it is prime and its reverse (1250286563) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3656820521 - 2⁶ = 3656820457 is a prime.

It is a super-2 number, since 2×3656820521² = 26744672645613422882, which contains 22 as substring.

Together with 3656820523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (3656820523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1828410260 + 1828410261.

It is an arithmetic number, because the mean of its divisors is an integer number (1828410261).

Almost surely, 2^3656820521 is an apocalyptic number.

It is an amenable number.

3656820521 is a deficient number, since it is larger than the sum of its proper divisors (1).

3656820521 is an equidigital number, since it uses as much as digits as its factorization.

3656820521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 86400, while the sum is 38.

The square root of 3656820521 is about 60471.6505562731. The cubic root of 3656820521 is about 1540.6401623974.

The spelling of 3656820521 in words is "three billion, six hundred fifty-six million, eight hundred twenty thousand, five hundred twenty-one".