618434821 has 2 divisors, whose sum is σ = 618434822. Its totient is φ = 618434820.

The previous prime is 618434813. The next prime is 618434837. The reversal of 618434821 is 128434816.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 377874721 + 240560100 = 19439^2 + 15510^2 .

It is a cyclic number.

It is not a de Polignac number, because 618434821 - 2³ = 618434813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (618434801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 309217410 + 309217411.

It is an arithmetic number, because the mean of its divisors is an integer number (309217411).

Almost surely, 2^618434821 is an apocalyptic number.

It is an amenable number.

618434821 is a deficient number, since it is larger than the sum of its proper divisors (1).

618434821 is an equidigital number, since it uses as much as digits as its factorization.

618434821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36864, while the sum is 37.

The square root of 618434821 is about 24868.3497844147. The cubic root of 618434821 is about 851.9837500666.

The spelling of 618434821 in words is "six hundred eighteen million, four hundred thirty-four thousand, eight hundred twenty-one".