641555 has 4 divisors (see below), whose sum is σ = 769872. Its totient is φ = 513240.

The previous prime is 641551. The next prime is 641579. The reversal of 641555 is 555146.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 641555 - 2² = 641551 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64151 + ... + 64160.

It is an arithmetic number, because the mean of its divisors is an integer number (192468).

2⁶⁴¹⁵⁵⁵ is an apocalyptic number.

641555 is a deficient number, since it is larger than the sum of its proper divisors (128317).

641555 is a wasteful number, since it uses less digits than its factorization.

641555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128316.

The product of its digits is 3000, while the sum is 26.

The square root of 641555 is about 800.9712853779. The cubic root of 641555 is about 86.2471258582.

The spelling of 641555 in words is "six hundred forty-one thousand, five hundred fifty-five".