640515611 has 2 divisors, whose sum is σ = 640515612. Its totient is φ = 640515610.

The previous prime is 640515607. The next prime is 640515643. The reversal of 640515611 is 116515046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640515611 - 2² = 640515607 is a prime.

It is not a weakly prime, because it can be changed into another prime (640515011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320257805 + 320257806.

It is an arithmetic number, because the mean of its divisors is an integer number (320257806).

Almost surely, 2^640515611 is an apocalyptic number.

640515611 is a deficient number, since it is larger than the sum of its proper divisors (1).

640515611 is an equidigital number, since it uses as much as digits as its factorization.

640515611 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3600, while the sum is 29.

The square root of 640515611 is about 25308.4098868341. The cubic root of 640515611 is about 862.0052410216.

The spelling of 640515611 in words is "six hundred forty million, five hundred fifteen thousand, six hundred eleven".