16997993 has 2 divisors, whose sum is σ = 16997994. Its totient is φ = 16997992.

The previous prime is 16997963. The next prime is 16997999. The reversal of 16997993 is 39979961.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13601344 + 3396649 = 3688^2 + 1843^2 .

It is a cyclic number.

It is not a de Polignac number, because 16997993 - 2¹⁴ = 16981609 is a prime.

It is not a weakly prime, because it can be changed into another prime (16997999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8498996 + 8498997.

It is an arithmetic number, because the mean of its divisors is an integer number (8498997).

Almost surely, 2^16997993 is an apocalyptic number.

It is an amenable number.

16997993 is a deficient number, since it is larger than the sum of its proper divisors (1).

16997993 is an equidigital number, since it uses as much as digits as its factorization.

16997993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 826686, while the sum is 53.

The square root of 16997993 is about 4122.8622339341. The cubic root of 16997993 is about 257.1180399183.

The spelling of 16997993 in words is "sixteen million, nine hundred ninety-seven thousand, nine hundred ninety-three".