640522999 has 2 divisors, whose sum is σ = 640523000. Its totient is φ = 640522998.

The previous prime is 640522973. The next prime is 640523011. The reversal of 640522999 is 999225046.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 640522999 - 2⁷ = 640522871 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640522199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320261499 + 320261500.

It is an arithmetic number, because the mean of its divisors is an integer number (320261500).

Almost surely, 2^640522999 is an apocalyptic number.

640522999 is a deficient number, since it is larger than the sum of its proper divisors (1).

640522999 is an equidigital number, since it uses as much as digits as its factorization.

640522999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 349920, while the sum is 46.

The square root of 640522999 is about 25308.5558458004. Note that the first 3 decimals coincide. The cubic root of 640522999 is about 862.0085552631.

The spelling of 640522999 in words is "six hundred forty million, five hundred twenty-two thousand, nine hundred ninety-nine".