640212077 has 2 divisors, whose sum is σ = 640212078. Its totient is φ = 640212076.

The previous prime is 640212071. The next prime is 640212103. The reversal of 640212077 is 770212046.

640212077 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 604618921 + 35593156 = 24589^2 + 5966^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640212077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640212071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320106038 + 320106039.

It is an arithmetic number, because the mean of its divisors is an integer number (320106039).

Almost surely, 2^640212077 is an apocalyptic number.

It is an amenable number.

640212077 is a deficient number, since it is larger than the sum of its proper divisors (1).

640212077 is an equidigital number, since it uses as much as digits as its factorization.

640212077 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4704, while the sum is 29.

The square root of 640212077 is about 25302.4124739124. The cubic root of 640212077 is about 861.8690542600.

The spelling of 640212077 in words is "six hundred forty million, two hundred twelve thousand, seventy-seven".