1818398641 has 2 divisors, whose sum is σ = 1818398642. Its totient is φ = 1818398640.

The previous prime is 1818398609. The next prime is 1818398669. The reversal of 1818398641 is 1468938181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1290318241 + 528080400 = 35921^2 + 22980^2 .

It is an emirp because it is prime and its reverse (1468938181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1818398641 - 2⁵ = 1818398609 is a prime.

It is not a weakly prime, because it can be changed into another prime (1818398941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 909199320 + 909199321.

It is an arithmetic number, because the mean of its divisors is an integer number (909199321).

Almost surely, 2^1818398641 is an apocalyptic number.

It is an amenable number.

1818398641 is a deficient number, since it is larger than the sum of its proper divisors (1).

1818398641 is an equidigital number, since it uses as much as digits as its factorization.

1818398641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 331776, while the sum is 49.

The square root of 1818398641 is about 42642.6856682362. The cubic root of 1818398641 is about 1220.5709593464.

The spelling of 1818398641 in words is "one billion, eight hundred eighteen million, three hundred ninety-eight thousand, six hundred forty-one".