16861601 has 2 divisors, whose sum is σ = 16861602. Its totient is φ = 16861600.

The previous prime is 16861597. The next prime is 16861609. The reversal of 16861601 is 10616861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9759376 + 7102225 = 3124^2 + 2665^2 .

It is a cyclic number.

It is not a de Polignac number, because 16861601 - 2² = 16861597 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (16861609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8430800 + 8430801.

It is an arithmetic number, because the mean of its divisors is an integer number (8430801).

Almost surely, 2^16861601 is an apocalyptic number.

It is an amenable number.

16861601 is a deficient number, since it is larger than the sum of its proper divisors (1).

16861601 is an equidigital number, since it uses as much as digits as its factorization.

16861601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 16861601 is about 4106.2879830816. The cubic root of 16861601 is about 256.4284867140.

The spelling of 16861601 in words is "sixteen million, eight hundred sixty-one thousand, six hundred one".