640590031 has 2 divisors, whose sum is σ = 640590032. Its totient is φ = 640590030.

The previous prime is 640590011. The next prime is 640590047. The reversal of 640590031 is 130095046.

640590031 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 640590031 - 2⁹ = 640589519 is a prime.

It is a super-2 number, since 2×640590031² = 820711175633161922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640590001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320295015 + 320295016.

It is an arithmetic number, because the mean of its divisors is an integer number (320295016).

Almost surely, 2^640590031 is an apocalyptic number.

640590031 is a deficient number, since it is larger than the sum of its proper divisors (1).

640590031 is an equidigital number, since it uses as much as digits as its factorization.

640590031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 640590031 is about 25309.8801063932. The cubic root of 640590031 is about 862.0386245148.

The spelling of 640590031 in words is "six hundred forty million, five hundred ninety thousand, thirty-one".