16945661 has 2 divisors, whose sum is σ = 16945662. Its totient is φ = 16945660.

The previous prime is 16945639. The next prime is 16945699. The reversal of 16945661 is 16654961.

It is an a-pointer prime, because the next prime (16945699) can be obtained adding 16945661 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10725625 + 6220036 = 3275^2 + 2494^2 .

It is a cyclic number.

It is not a de Polignac number, because 16945661 - 2⁶ = 16945597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16945631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8472830 + 8472831.

It is an arithmetic number, because the mean of its divisors is an integer number (8472831).

Almost surely, 2^16945661 is an apocalyptic number.

It is an amenable number.

16945661 is a deficient number, since it is larger than the sum of its proper divisors (1).

16945661 is an equidigital number, since it uses as much as digits as its factorization.

16945661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 38.

The square root of 16945661 is about 4116.5107797745. The cubic root of 16945661 is about 256.8539041565.

The spelling of 16945661 in words is "sixteen million, nine hundred forty-five thousand, six hundred sixty-one".