643615 has 24 divisors (see below), whose sum is σ = 935712. Its totient is φ = 423360.

The previous prime is 643589. The next prime is 643619. The reversal of 643615 is 516346.

It is not a de Polignac number, because 643615 - 2⁵ = 643583 is a prime.

It is a Duffinian number.

Its product of digits (2160) is a multiple of the sum of its prime divisors (120).

It is a self number, because there is not a number n which added to its sum of digits gives 643615.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643619) 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 23 ways as a sum of consecutive naturals, for example, 9030 + ... + 9100.

It is an arithmetic number, because the mean of its divisors is an integer number (38988).

2⁶⁴³⁶¹⁵ is an apocalyptic number.

643615 is a deficient number, since it is larger than the sum of its proper divisors (292097).

643615 is a wasteful number, since it uses less digits than its factorization.

643615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127 (or 120 counting only the distinct ones).

The product of its digits is 2160, while the sum is 25.

The square root of 643615 is about 802.2561934943. The cubic root of 643615 is about 86.3393389216.

The spelling of 643615 in words is "six hundred forty-three thousand, six hundred fifteen".