918568621 has 2 divisors, whose sum is σ = 918568622. Its totient is φ = 918568620.

The previous prime is 918568619. The next prime is 918568643. The reversal of 918568621 is 126865819.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 906913225 + 11655396 = 30115^2 + 3414^2 .

It is an emirp because it is prime and its reverse (126865819) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 918568621 - 2¹ = 918568619 is a prime.

It is a super-2 number, since 2×918568621² = 1687536622971683282, which contains 22 as substring.

Together with 918568619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (918568691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 459284310 + 459284311.

It is an arithmetic number, because the mean of its divisors is an integer number (459284311).

Almost surely, 2^918568621 is an apocalyptic number.

It is an amenable number.

918568621 is a deficient number, since it is larger than the sum of its proper divisors (1).

918568621 is an equidigital number, since it uses as much as digits as its factorization.

918568621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 207360, while the sum is 46.

The square root of 918568621 is about 30307.8970072158. The cubic root of 918568621 is about 972.0841646850.

The spelling of 918568621 in words is "nine hundred eighteen million, five hundred sixty-eight thousand, six hundred twenty-one".