640811067 has 8 divisors (see below), whose sum is σ = 920139024. Its totient is φ = 394345248.

The previous prime is 640811063. The next prime is 640811071. The reversal of 640811067 is 760118046.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (640811063) and next prime (640811071).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 640811067 - 2² = 640811063 is a prime.

It is not an unprimeable number, because it can be changed into a prime (640811063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8215488 + ... + 8215565.

It is an arithmetic number, because the mean of its divisors is an integer number (115017378).

Almost surely, 2^640811067 is an apocalyptic number.

640811067 is a deficient number, since it is larger than the sum of its proper divisors (279327957).

640811067 is a wasteful number, since it uses less digits than its factorization.

640811067 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16431069.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 640811067 is about 25314.2463249452. The cubic root of 640811067 is about 862.1377621062.

The spelling of 640811067 in words is "six hundred forty million, eight hundred eleven thousand, sixty-seven".