618561 has 6 divisors (see below), whose sum is σ = 893490. Its totient is φ = 412368.

The previous prime is 618559. The next prime is 618571. The reversal of 618561 is 165816.

It can be written as a sum of positive squares in only one way, i.e., 553536 + 65025 = 744^2 + 255^2 .

It is not a de Polignac number, because 618561 - 2¹ = 618559 is a prime.

It is an Ulam number.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (618521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 34356 + ... + 34373.

It is an arithmetic number, because the mean of its divisors is an integer number (148915).

2⁶¹⁸⁵⁶¹ is an apocalyptic number.

It is an amenable number.

618561 is a deficient number, since it is larger than the sum of its proper divisors (274929).

618561 is a wasteful number, since it uses less digits than its factorization.

618561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68735 (or 68732 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 618561 is about 786.4864906659. The cubic root of 618561 is about 85.2041689423.

The spelling of 618561 in words is "six hundred eighteen thousand, five hundred sixty-one".