409645561 has 32 divisors (see below), whose sum is σ = 474969600. Its totient is φ = 350542080.

The previous prime is 409645547. The next prime is 409645609. The reversal of 409645561 is 165546904.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 409645561 - 2¹⁵ = 409612793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (409645661) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1080670 + ... + 1081048.

It is an arithmetic number, because the mean of its divisors is an integer number (14842800).

Almost surely, 2^409645561 is an apocalyptic number.

It is an amenable number.

409645561 is a deficient number, since it is larger than the sum of its proper divisors (65324039).

409645561 is a wasteful number, since it uses less digits than its factorization.

409645561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 529.

The product of its (nonzero) digits is 129600, while the sum is 40.

The square root of 409645561 is about 20239.7025916884. The cubic root of 409645561 is about 742.6817482203.

The spelling of 409645561 in words is "four hundred nine million, six hundred forty-five thousand, five hundred sixty-one".