664774577 has 4 divisors (see below), whose sum is σ = 666354036. Its totient is φ = 663195120.

The previous prime is 664774567. The next prime is 664774609. The reversal of 664774577 is 775477466.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15085456 + 649689121 = 3884^2 + 25489^2 .

It is a cyclic number.

It is not a de Polignac number, because 664774577 - 2¹⁶ = 664709041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664774507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 789098 + ... + 789939.

It is an arithmetic number, because the mean of its divisors is an integer number (166588509).

Almost surely, 2^664774577 is an apocalyptic number.

It is an amenable number.

664774577 is a deficient number, since it is larger than the sum of its proper divisors (1579459).

664774577 is a wasteful number, since it uses less digits than its factorization.

664774577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1579458.

The product of its digits is 6914880, while the sum is 53.

The square root of 664774577 is about 25783.2227814911. Note that the first 3 decimals coincide. The cubic root of 664774577 is about 872.7532353608.

The spelling of 664774577 in words is "six hundred sixty-four million, seven hundred seventy-four thousand, five hundred seventy-seven".