640000019 has 2 divisors, whose sum is σ = 640000020. Its totient is φ = 640000018.

The previous prime is 639999967. The next prime is 640000027. The reversal of 640000019 is 910000046.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640000019 is a prime.

It is a super-2 number, since 2×640000019² = 819200048640000722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (640000099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320000009 + 320000010.

It is an arithmetic number, because the mean of its divisors is an integer number (320000010).

Almost surely, 2^640000019 is an apocalyptic number.

640000019 is a deficient number, since it is larger than the sum of its proper divisors (1).

640000019 is an equidigital number, since it uses as much as digits as its factorization.

640000019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 640000019 is about 25298.2216568675. The cubic root of 640000019 is about 861.7738845407.

The spelling of 640000019 in words is "six hundred forty million, nineteen", and thus it is an aban number.