18895661 has 2 divisors, whose sum is σ = 18895662. Its totient is φ = 18895660.

The previous prime is 18895651. The next prime is 18895663. The reversal of 18895661 is 16659881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18541636 + 354025 = 4306^2 + 595^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18895661 is a prime.

Together with 18895663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18895663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9447830 + 9447831.

It is an arithmetic number, because the mean of its divisors is an integer number (9447831).

Almost surely, 2^18895661 is an apocalyptic number.

It is an amenable number.

18895661 is a deficient number, since it is larger than the sum of its proper divisors (1).

18895661 is an equidigital number, since it uses as much as digits as its factorization.

18895661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 44.

The square root of 18895661 is about 4346.9139628017. The cubic root of 18895661 is about 266.3508147539.

The spelling of 18895661 in words is "eighteen million, eight hundred ninety-five thousand, six hundred sixty-one".