866630561 has 8 divisors (see below), whose sum is σ = 875203080. Its totient is φ = 858074112.

The previous prime is 866630537. The next prime is 866630621. The reversal of 866630561 is 165036668.

It can be written as a sum of positive squares in 4 ways, for example, as 135955600 + 730674961 = 11660^2 + 27031^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-866630561 is a prime.

It is not an unprimeable number, because it can be changed into a prime (866630861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 124181 + ... + 130973.

It is an arithmetic number, because the mean of its divisors is an integer number (109400385).

Almost surely, 2^866630561 is an apocalyptic number.

It is an amenable number.

866630561 is a deficient number, since it is larger than the sum of its proper divisors (8572519).

866630561 is a wasteful number, since it uses less digits than its factorization.

866630561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8035.

The product of its (nonzero) digits is 155520, while the sum is 41.

The square root of 866630561 is about 29438.5896571150. The cubic root of 866630561 is about 953.4062618695.

The spelling of 866630561 in words is "eight hundred sixty-six million, six hundred thirty thousand, five hundred sixty-one".