618572221 has 2 divisors, whose sum is σ = 618572222. Its totient is φ = 618572220.

The previous prime is 618572209. The next prime is 618572231. The reversal of 618572221 is 122275816.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 459459225 + 159112996 = 21435^2 + 12614^2 .

It is a cyclic number.

It is not a de Polignac number, because 618572221 - 2¹³ = 618564029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (618572231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 309286110 + 309286111.

It is an arithmetic number, because the mean of its divisors is an integer number (309286111).

Almost surely, 2^618572221 is an apocalyptic number.

It is an amenable number.

618572221 is a deficient number, since it is larger than the sum of its proper divisors (1).

618572221 is an equidigital number, since it uses as much as digits as its factorization.

618572221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13440, while the sum is 34.

The square root of 618572221 is about 24871.1121785898. The cubic root of 618572221 is about 852.0468415436.

The spelling of 618572221 in words is "six hundred eighteen million, five hundred seventy-two thousand, two hundred twenty-one".