640187 has 8 divisors (see below), whose sum is σ = 668736. Its totient is φ = 612352.

The previous prime is 640163. The next prime is 640193. The reversal of 640187 is 781046.

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 640187 - 2¹⁴ = 623803 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640187.

It is not an unprimeable number, because it can be changed into a prime (640127) 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, 2363 + ... + 2619.

It is an arithmetic number, because the mean of its divisors is an integer number (83592).

2⁶⁴⁰¹⁸⁷ is an apocalyptic number.

640187 is a deficient number, since it is larger than the sum of its proper divisors (28549).

640187 is a wasteful number, since it uses less digits than its factorization.

640187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 640187 is about 800.1168664639. The cubic root of 640187 is about 86.1857801024.

The spelling of 640187 in words is "six hundred forty thousand, one hundred eighty-seven".