561001687 has 2 divisors, whose sum is σ = 561001688. Its totient is φ = 561001686.

The previous prime is 561001643. The next prime is 561001741. The reversal of 561001687 is 786100165.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 561001687 - 2¹⁹ = 560477399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561004687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280500843 + 280500844.

It is an arithmetic number, because the mean of its divisors is an integer number (280500844).

Almost surely, 2^561001687 is an apocalyptic number.

561001687 is a deficient number, since it is larger than the sum of its proper divisors (1).

561001687 is an equidigital number, since it uses as much as digits as its factorization.

561001687 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 561001687 is about 23685.4741772252. The cubic root of 561001687 is about 824.7482241190.

The spelling of 561001687 in words is "five hundred sixty-one million, one thousand, six hundred eighty-seven".