1898393561 has 2 divisors, whose sum is σ = 1898393562. Its totient is φ = 1898393560.

The previous prime is 1898393557. The next prime is 1898393597. The reversal of 1898393561 is 1653938981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1885296400 + 13097161 = 43420^2 + 3619^2 .

It is a cyclic number.

It is not a de Polignac number, because 1898393561 - 2² = 1898393557 is a prime.

It is a super-2 number, since 2×1898393561² = 7207796224892521442, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1898393551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 949196780 + 949196781.

It is an arithmetic number, because the mean of its divisors is an integer number (949196781).

Almost surely, 2^1898393561 is an apocalyptic number.

It is an amenable number.

1898393561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1898393561 is an equidigital number, since it uses as much as digits as its factorization.

1898393561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1399680, while the sum is 53.

The square root of 1898393561 is about 43570.5584196485. The cubic root of 1898393561 is about 1238.2131654465.

The spelling of 1898393561 in words is "one billion, eight hundred ninety-eight million, three hundred ninety-three thousand, five hundred sixty-one".