640415 has 8 divisors (see below), whose sum is σ = 772800. Its totient is φ = 509472.

The previous prime is 640411. The next prime is 640421. The reversal of 640415 is 514046.

It is a happy number.

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 640415 - 2² = 640411 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640411) 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, 1562 + ... + 1928.

It is an arithmetic number, because the mean of its divisors is an integer number (96600).

2⁶⁴⁰⁴¹⁵ is an apocalyptic number.

640415 is a deficient number, since it is larger than the sum of its proper divisors (132385).

640415 is a wasteful number, since it uses less digits than its factorization.

640415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 721.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 640415 is about 800.2593329665. The cubic root of 640415 is about 86.1960104599.

It can be divided in two parts, 64041 and 5, that added together give a palindrome (64046).

The spelling of 640415 in words is "six hundred forty thousand, four hundred fifteen".