618521 has 2 divisors, whose sum is σ = 618522. Its totient is φ = 618520.

The previous prime is 618509. The next prime is 618547. The reversal of 618521 is 125816.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 403225 + 215296 = 635^2 + 464^2 .

It is a cyclic number.

It is not a de Polignac number, because 618521 - 2¹⁴ = 602137 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

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

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (618571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 309260 + 309261.

It is an arithmetic number, because the mean of its divisors is an integer number (309261).

2⁶¹⁸⁵²¹ is an apocalyptic number.

It is an amenable number.

618521 is a deficient number, since it is larger than the sum of its proper divisors (1).

618521 is an equidigital number, since it uses as much as digits as its factorization.

618521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 480, while the sum is 23.

The square root of 618521 is about 786.4610607017. The cubic root of 618521 is about 85.2023322923.

The spelling of 618521 in words is "six hundred eighteen thousand, five hundred twenty-one".