618981 has 8 divisors (see below), whose sum is σ = 900384. Its totient is φ = 375120.

The previous prime is 618979. The next prime is 618991. The reversal of 618981 is 189816.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 618981 - 2¹ = 618979 is a prime.

It is a super-2 number, since 2×618981² = 766274956722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 18757 = 618981 / (6 + 1 + 8 + 9 + 8 + 1).

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

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 618981.

It is not an unprimeable number, because it can be changed into a prime (618941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9346 + ... + 9411.

It is an arithmetic number, because the mean of its divisors is an integer number (112548).

2⁶¹⁸⁹⁸¹ is an apocalyptic number.

It is an amenable number.

618981 is a deficient number, since it is larger than the sum of its proper divisors (281403).

618981 is a wasteful number, since it uses less digits than its factorization.

618981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18771.

The product of its digits is 3456, while the sum is 33.

The square root of 618981 is about 786.7534556645. The cubic root of 618981 is about 85.2234489889.

The spelling of 618981 in words is "six hundred eighteen thousand, nine hundred eighty-one".