640465031 has 2 divisors, whose sum is σ = 640465032. Its totient is φ = 640465030.

The previous prime is 640465019. The next prime is 640465037. The reversal of 640465031 is 130564046.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 640465031 - 2¹⁴ = 640448647 is a prime.

It is a super-2 number, since 2×640465031² = 820390911867661922, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 640464985 and 640465003.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640465037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320232515 + 320232516.

It is an arithmetic number, because the mean of its divisors is an integer number (320232516).

Almost surely, 2^640465031 is an apocalyptic number.

640465031 is a deficient number, since it is larger than the sum of its proper divisors (1).

640465031 is an equidigital number, since it uses as much as digits as its factorization.

640465031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 640465031 is about 25307.4105945274. The cubic root of 640465031 is about 861.9825502539.

The spelling of 640465031 in words is "six hundred forty million, four hundred sixty-five thousand, thirty-one".