64561409 has 16 divisors (see below), whose sum is σ = 72493056. Its totient is φ = 56994000.

The previous prime is 64561403. The next prime is 64561421. The reversal of 64561409 is 90416546.

It is a cyclic number.

It is not a de Polignac number, because 64561409 - 2⁸ = 64561153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64561403) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77654 + ... + 78480.

It is an arithmetic number, because the mean of its divisors is an integer number (4530816).

Almost surely, 2^64561409 is an apocalyptic number.

It is an amenable number.

64561409 is a deficient number, since it is larger than the sum of its proper divisors (7931647).

64561409 is a wasteful number, since it uses less digits than its factorization.

64561409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1036.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 64561409 is about 8035.0114498985. The cubic root of 64561409 is about 401.1661987304.

The spelling of 64561409 in words is "sixty-four million, five hundred sixty-one thousand, four hundred nine".