640713019 has 2 divisors, whose sum is σ = 640713020. Its totient is φ = 640713018.

The previous prime is 640712987. The next prime is 640713049. The reversal of 640713019 is 910317046.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 640713019 - 2⁵ = 640712987 is a prime.

It is a super-2 number, since 2×640713019² = 821026345432188722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (640713049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320356509 + 320356510.

It is an arithmetic number, because the mean of its divisors is an integer number (320356510).

Almost surely, 2^640713019 is an apocalyptic number.

640713019 is a deficient number, since it is larger than the sum of its proper divisors (1).

640713019 is an equidigital number, since it uses as much as digits as its factorization.

640713019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 640713019 is about 25312.3096338521. The cubic root of 640713019 is about 862.0937890855.

The spelling of 640713019 in words is "six hundred forty million, seven hundred thirteen thousand, nineteen".