366681661 has 2 divisors, whose sum is σ = 366681662. Its totient is φ = 366681660.

The previous prime is 366681659. The next prime is 366681767. The reversal of 366681661 is 166186663.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 327067225 + 39614436 = 18085^2 + 6294^2 .

It is an emirp because it is prime and its reverse (166186663) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 366681661 - 2¹ = 366681659 is a prime.

Together with 366681659, 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 (366681641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 183340830 + 183340831.

It is an arithmetic number, because the mean of its divisors is an integer number (183340831).

Almost surely, 2^366681661 is an apocalyptic number.

It is an amenable number.

366681661 is a deficient number, since it is larger than the sum of its proper divisors (1).

366681661 is an equidigital number, since it uses as much as digits as its factorization.

366681661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 186624, while the sum is 43.

The square root of 366681661 is about 19148.9336778840. The cubic root of 366681661 is about 715.7528126521.

The spelling of 366681661 in words is "three hundred sixty-six million, six hundred eighty-one thousand, six hundred sixty-one".