654620809 has 2 divisors, whose sum is σ = 654620810. Its totient is φ = 654620808.

The previous prime is 654620807. The next prime is 654620821. The reversal of 654620809 is 908026456.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 427455625 + 227165184 = 20675^2 + 15072^2 .

It is a cyclic number.

It is not a de Polignac number, because 654620809 - 2¹ = 654620807 is a prime.

Together with 654620807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (654620807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327310404 + 327310405.

It is an arithmetic number, because the mean of its divisors is an integer number (327310405).

Almost surely, 2^654620809 is an apocalyptic number.

It is an amenable number.

654620809 is a deficient number, since it is larger than the sum of its proper divisors (1).

654620809 is an equidigital number, since it uses as much as digits as its factorization.

654620809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 40.

The square root of 654620809 is about 25585.5586024617. The cubic root of 654620809 is about 868.2869400573.

The spelling of 654620809 in words is "six hundred fifty-four million, six hundred twenty thousand, eight hundred nine".