16665949 has 2 divisors, whose sum is σ = 16665950. Its totient is φ = 16665948.

The previous prime is 16665911. The next prime is 16665953. The reversal of 16665949 is 94956661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13741849 + 2924100 = 3707^2 + 1710^2 .

It is a cyclic number.

It is not a de Polignac number, because 16665949 - 2¹⁵ = 16633181 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16665899 and 16665908.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16665349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8332974 + 8332975.

It is an arithmetic number, because the mean of its divisors is an integer number (8332975).

Almost surely, 2^16665949 is an apocalyptic number.

It is an amenable number.

16665949 is a deficient number, since it is larger than the sum of its proper divisors (1).

16665949 is an equidigital number, since it uses as much as digits as its factorization.

16665949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 349920, while the sum is 46.

The square root of 16665949 is about 4082.3950078355. The cubic root of 16665949 is about 255.4328110470.

The spelling of 16665949 in words is "sixteen million, six hundred sixty-five thousand, nine hundred forty-nine".