3688906021 has 2 divisors, whose sum is σ = 3688906022. Its totient is φ = 3688906020.

The previous prime is 3688906019. The next prime is 3688906063. The reversal of 3688906021 is 1206098863.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2065702500 + 1623203521 = 45450^2 + 40289^2 .

It is a cyclic number.

It is not a de Polignac number, because 3688906021 - 2¹ = 3688906019 is a prime.

Together with 3688906019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3688906321) 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, 1844453010 + 1844453011.

It is an arithmetic number, because the mean of its divisors is an integer number (1844453011).

Almost surely, 2^3688906021 is an apocalyptic number.

It is an amenable number.

3688906021 is a deficient number, since it is larger than the sum of its proper divisors (1).

3688906021 is an equidigital number, since it uses as much as digits as its factorization.

3688906021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 3688906021 is about 60736.3648978106. The cubic root of 3688906021 is about 1545.1329847862.

The spelling of 3688906021 in words is "three billion, six hundred eighty-eight million, nine hundred six thousand, twenty-one".