640494576149 has 2 divisors, whose sum is σ = 640494576150. Its totient is φ = 640494576148.

The previous prime is 640494576083. The next prime is 640494576173. The reversal of 640494576149 is 941675494046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 451980567025 + 188514009124 = 672295^2 + 434182^2 .

It is a cyclic number.

It is not a de Polignac number, because 640494576149 - 2⁸ = 640494575893 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640494576179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320247288074 + 320247288075.

It is an arithmetic number, because the mean of its divisors is an integer number (320247288075).

Almost surely, 2^640494576149 is an apocalyptic number.

It is an amenable number.

640494576149 is a deficient number, since it is larger than the sum of its proper divisors (1).

640494576149 is an equidigital number, since it uses as much as digits as its factorization.

640494576149 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 26127360, while the sum is 59.

The spelling of 640494576149 in words is "six hundred forty billion, four hundred ninety-four million, five hundred seventy-six thousand, one hundred forty-nine".