656650409 has 2 divisors, whose sum is σ = 656650410. Its totient is φ = 656650408.

The previous prime is 656650399. The next prime is 656650411. The reversal of 656650409 is 904056656.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 439824784 + 216825625 = 20972^2 + 14725^2 .

It is a cyclic number.

It is not a de Polignac number, because 656650409 - 2¹² = 656646313 is a prime.

Together with 656650411, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (656650429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328325204 + 328325205.

It is an arithmetic number, because the mean of its divisors is an integer number (328325205).

Almost surely, 2^656650409 is an apocalyptic number.

It is an amenable number.

656650409 is a deficient number, since it is larger than the sum of its proper divisors (1).

656650409 is an equidigital number, since it uses as much as digits as its factorization.

656650409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 194400, while the sum is 41.

The square root of 656650409 is about 25625.1909066059. The cubic root of 656650409 is about 869.1833659041.

The spelling of 656650409 in words is "six hundred fifty-six million, six hundred fifty thousand, four hundred nine".