1858218161 has 2 divisors, whose sum is σ = 1858218162. Its totient is φ = 1858218160.

The previous prime is 1858218149. The next prime is 1858218227. The reversal of 1858218161 is 1618128581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1604803600 + 253414561 = 40060^2 + 15919^2 .

It is a cyclic number.

It is not a de Polignac number, because 1858218161 - 2¹⁸ = 1857956017 is a prime.

It is not a weakly prime, because it can be changed into another prime (1858208161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 929109080 + 929109081.

It is an arithmetic number, because the mean of its divisors is an integer number (929109081).

Almost surely, 2^1858218161 is an apocalyptic number.

It is an amenable number.

1858218161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1858218161 is an equidigital number, since it uses as much as digits as its factorization.

1858218161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30720, while the sum is 41.

The square root of 1858218161 is about 43107.0546546618. The cubic root of 1858218161 is about 1229.4161110408.

The spelling of 1858218161 in words is "one billion, eight hundred fifty-eight million, two hundred eighteen thousand, one hundred sixty-one".