561690001 has 4 divisors (see below), whose sum is σ = 562265892. Its totient is φ = 561114112.

The previous prime is 561689983. The next prime is 561690029. The reversal of 561690001 is 100096165.

561690001 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Cunningham number, because it is equal to 23700²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 525509776 + 36180225 = 22924^2 + 6015^2 .

It is a cyclic number.

It is not a de Polignac number, because 561690001 - 2¹¹ = 561687953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561690601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 286480 + ... + 288433.

It is an arithmetic number, because the mean of its divisors is an integer number (140566473).

Almost surely, 2^561690001 is an apocalyptic number.

It is an amenable number.

561690001 is a deficient number, since it is larger than the sum of its proper divisors (575891).

561690001 is an equidigital number, since it uses as much as digits as its factorization.

561690001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 575890.

The product of its (nonzero) digits is 1620, while the sum is 28.

The square root of 561690001 is about 23700.0000210970. Note that the first 4 decimals coincide. The cubic root of 561690001 is about 825.0853911001.

The spelling of 561690001 in words is "five hundred sixty-one million, six hundred ninety thousand, one".