640534367 has 8 divisors (see below), whose sum is σ = 698947920. Its totient is φ = 582151360.

The previous prime is 640534361. The next prime is 640534373. The reversal of 640534367 is 763435046.

It is an interprime number because it is at equal distance from previous prime (640534361) and next prime (640534373).

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

It is a cyclic number.

It is not a de Polignac number, because 640534367 - 2¹⁸ = 640272223 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 640534367.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640534361) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79643 + ... + 87315.

It is an arithmetic number, because the mean of its divisors is an integer number (87368490).

Almost surely, 2^640534367 is an apocalyptic number.

640534367 is a deficient number, since it is larger than the sum of its proper divisors (58413553).

640534367 is a wasteful number, since it uses less digits than its factorization.

640534367 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15273.

The product of its (nonzero) digits is 181440, while the sum is 38.

The square root of 640534367 is about 25308.7804328853. The cubic root of 640534367 is about 862.0136548746.

The spelling of 640534367 in words is "six hundred forty million, five hundred thirty-four thousand, three hundred sixty-seven".