655636409 has 2 divisors, whose sum is σ = 655636410. Its totient is φ = 655636408.

The previous prime is 655636381. The next prime is 655636441. The reversal of 655636409 is 904636556.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 456036025 + 199600384 = 21355^2 + 14128^2 .

It is a cyclic number.

It is not a de Polignac number, because 655636409 - 2⁸ = 655636153 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 655636409.

It is not a weakly prime, because it can be changed into another prime (655636469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327818204 + 327818205.

It is an arithmetic number, because the mean of its divisors is an integer number (327818205).

Almost surely, 2^655636409 is an apocalyptic number.

It is an amenable number.

655636409 is a deficient number, since it is larger than the sum of its proper divisors (1).

655636409 is an equidigital number, since it uses as much as digits as its factorization.

655636409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 583200, while the sum is 44.

The square root of 655636409 is about 25605.3980441625. The cubic root of 655636409 is about 868.7357375710.

The spelling of 655636409 in words is "six hundred fifty-five million, six hundred thirty-six thousand, four hundred nine".