640366169 has 2 divisors, whose sum is σ = 640366170. Its totient is φ = 640366168.

The previous prime is 640366127. The next prime is 640366213. The reversal of 640366169 is 961663046.

640366169 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 532455625 + 107910544 = 23075^2 + 10388^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640366169 is a prime.

It is a super-2 number, since 2×640366169² = 820137660799473122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (640360169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320183084 + 320183085.

It is an arithmetic number, because the mean of its divisors is an integer number (320183085).

Almost surely, 2^640366169 is an apocalyptic number.

It is an amenable number.

640366169 is a deficient number, since it is larger than the sum of its proper divisors (1).

640366169 is an equidigital number, since it uses as much as digits as its factorization.

640366169 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 139968, while the sum is 41.

The square root of 640366169 is about 25305.4572967967. The cubic root of 640366169 is about 861.9381961779.

The spelling of 640366169 in words is "six hundred forty million, three hundred sixty-six thousand, one hundred sixty-nine".