641557 has 6 divisors (see below), whose sum is σ = 746358. Its totient is φ = 549864.

The previous prime is 641551. The next prime is 641579. The reversal of 641557 is 755146.

It can be written as a sum of positive squares in only one way, i.e., 625681 + 15876 = 791^2 + 126^2 .

It is not a de Polignac number, because 641557 - 2³ = 641549 is a prime.

It is a Duffinian number.

It is a congruent 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 5 ways as a sum of consecutive naturals, for example, 6498 + ... + 6595.

It is an arithmetic number, because the mean of its divisors is an integer number (124393).

2⁶⁴¹⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

641557 is a deficient number, since it is larger than the sum of its proper divisors (104801).

641557 is a wasteful number, since it uses less digits than its factorization.

641557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13107 (or 13100 counting only the distinct ones).

The product of its digits is 4200, while the sum is 28.

The square root of 641557 is about 800.9725338612. The cubic root of 641557 is about 86.2472154811.

The spelling of 641557 in words is "six hundred forty-one thousand, five hundred fifty-seven".