16007561 has 2 divisors, whose sum is σ = 16007562. Its totient is φ = 16007560.

The previous prime is 16007543. The next prime is 16007581. The reversal of 16007561 is 16570061.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12924025 + 3083536 = 3595^2 + 1756^2 .

It is an emirp because it is prime and its reverse (16570061) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16007561 - 2¹⁴ = 15991177 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16007561.

It is not a weakly prime, because it can be changed into another prime (16007531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8003780 + 8003781.

It is an arithmetic number, because the mean of its divisors is an integer number (8003781).

Almost surely, 2^16007561 is an apocalyptic number.

It is an amenable number.

16007561 is a deficient number, since it is larger than the sum of its proper divisors (1).

16007561 is an equidigital number, since it uses as much as digits as its factorization.

16007561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1260, while the sum is 26.

The square root of 16007561 is about 4000.9450133687. The cubic root of 16007561 is about 252.0238964909.

Subtracting 16007561 from its reverse (16570061), we obtain a square (562500 = 750²).

The spelling of 16007561 in words is "sixteen million, seven thousand, five hundred sixty-one".