39166021 has 2 divisors, whose sum is σ = 39166022. Its totient is φ = 39166020.

The previous prime is 39166019. The next prime is 39166097. The reversal of 39166021 is 12066193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 33477796 + 5688225 = 5786^2 + 2385^2 .

It is an emirp because it is prime and its reverse (12066193) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39166021 - 2¹ = 39166019 is a prime.

Together with 39166019, 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 (39166121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19583010 + 19583011.

It is an arithmetic number, because the mean of its divisors is an integer number (19583011).

Almost surely, 2^39166021 is an apocalyptic number.

It is an amenable number.

39166021 is a deficient number, since it is larger than the sum of its proper divisors (1).

39166021 is an equidigital number, since it uses as much as digits as its factorization.

39166021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 39166021 is about 6258.2762003606. The cubic root of 39166021 is about 339.6016701939.

The spelling of 39166021 in words is "thirty-nine million, one hundred sixty-six thousand, twenty-one".