16991057 has 2 divisors, whose sum is σ = 16991058. Its totient is φ = 16991056.

The previous prime is 16991033. The next prime is 16991099. The reversal of 16991057 is 75019961.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10042561 + 6948496 = 3169^2 + 2636^2 .

It is a cyclic number.

It is not a de Polignac number, because 16991057 - 2⁶ = 16990993 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 16991057.

It is not a weakly prime, because it can be changed into another prime (16991027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8495528 + 8495529.

It is an arithmetic number, because the mean of its divisors is an integer number (8495529).

Almost surely, 2^16991057 is an apocalyptic number.

It is an amenable number.

16991057 is a deficient number, since it is larger than the sum of its proper divisors (1).

16991057 is an equidigital number, since it uses as much as digits as its factorization.

16991057 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 16991057 is about 4122.0209849053. The cubic root of 16991057 is about 257.0830629782.

The spelling of 16991057 in words is "sixteen million, nine hundred ninety-one thousand, fifty-seven".