16501997 has 2 divisors, whose sum is σ = 16501998. Its totient is φ = 16501996.

The previous prime is 16501987. The next prime is 16502023. The reversal of 16501997 is 79910561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16434916 + 67081 = 4054^2 + 259^2 .

It is a cyclic number.

It is not a de Polignac number, because 16501997 - 2¹⁰ = 16500973 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16501997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16501907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8250998 + 8250999.

It is an arithmetic number, because the mean of its divisors is an integer number (8250999).

Almost surely, 2^16501997 is an apocalyptic number.

It is an amenable number.

16501997 is a deficient number, since it is larger than the sum of its proper divisors (1).

16501997 is an equidigital number, since it uses as much as digits as its factorization.

16501997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17010, while the sum is 38.

The square root of 16501997 is about 4062.2650085882. The cubic root of 16501997 is about 254.5924387876.

The spelling of 16501997 in words is "sixteen million, five hundred one thousand, nine hundred ninety-seven".