640306577 has 2 divisors, whose sum is σ = 640306578. Its totient is φ = 640306576.

The previous prime is 640306561. The next prime is 640306633. The reversal of 640306577 is 775603046.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 640292416 + 14161 = 25304^2 + 119^2 .

It is a cyclic number.

It is not a de Polignac number, because 640306577 - 2⁴ = 640306561 is a prime.

It is a super-4 number, since 4×640306577⁴ (a number of 36 digits) contains 4444 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 640306577.

It is not a weakly prime, because it can be changed into another prime (640302577) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320153288 + 320153289.

It is an arithmetic number, because the mean of its divisors is an integer number (320153289).

Almost surely, 2^640306577 is an apocalyptic number.

It is an amenable number.

640306577 is a deficient number, since it is larger than the sum of its proper divisors (1).

640306577 is an equidigital number, since it uses as much as digits as its factorization.

640306577 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 105840, while the sum is 38.

The square root of 640306577 is about 25304.2798158730. The cubic root of 640306577 is about 861.9114582391.

It can be divided in two parts, 64030 and 6577, that added together give a palindrome (70607).

The spelling of 640306577 in words is "six hundred forty million, three hundred six thousand, five hundred seventy-seven".