618644 has 12 divisors (see below), whose sum is σ = 1166004. Its totient is φ = 285504.

The previous prime is 618643. The next prime is 618671. The reversal of 618644 is 446816.

It can be written as a sum of positive squares in 2 ways, for example, as 407044 + 211600 = 638^2 + 460^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (618643) 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, 5897 + ... + 6000.

It is an arithmetic number, because the mean of its divisors is an integer number (97167).

2⁶¹⁸⁶⁴⁴ is an apocalyptic number.

It is an amenable number.

618644 is a deficient number, since it is larger than the sum of its proper divisors (547360).

618644 is a wasteful number, since it uses less digits than its factorization.

618644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11914 (or 11912 counting only the distinct ones).

The product of its digits is 4608, while the sum is 29.

The square root of 618644 is about 786.5392552187. The cubic root of 618644 is about 85.2079797385.

It can be divided in two parts, 61864 and 4, that multiplied together give a triangular number (247456 = T₇₀₃).

The spelling of 618644 in words is "six hundred eighteen thousand, six hundred forty-four".