2563642809 has 36 divisors (see below), whose sum is σ = 4638983076. Its totient is φ = 1352248128.

The previous prime is 2563642799. The next prime is 2563642819. The reversal of 2563642809 is 9082463652.

2563642809 is a `hidden beast` number, since 2 + 5 + 6 + 364 + 280 + 9 = 666.

2563642809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (2563642799) and next prime (2563642819).

It can be written as a sum of positive squares in 2 ways, for example, as 490844025 + 2072798784 = 22155^2 + 45528^2 .

It is not a de Polignac number, because 2563642809 - 2⁸ = 2563642553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2563642819) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 217854 + ... + 229319.

It is an arithmetic number, because the mean of its divisors is an integer number (128860641).

Almost surely, 2^2563642809 is an apocalyptic number.

It is an amenable number.

2563642809 is a deficient number, since it is larger than the sum of its proper divisors (2075340267).

2563642809 is a wasteful number, since it uses less digits than its factorization.

2563642809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447206 (or 447196 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The square root of 2563642809 is about 50632.4284327742. The cubic root of 2563642809 is about 1368.6293160374.

The spelling of 2563642809 in words is "two billion, five hundred sixty-three million, six hundred forty-two thousand, eight hundred nine".