1998961057 has 2 divisors, whose sum is σ = 1998961058. Its totient is φ = 1998961056.

The previous prime is 1998961037. The next prime is 1998961061. The reversal of 1998961057 is 7501698991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1142169616 + 856791441 = 33796^2 + 29271^2 .

It is a cyclic number.

It is not a de Polignac number, because 1998961057 - 2²⁷ = 1864743329 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1998960989 and 1998961007.

It is not a weakly prime, because it can be changed into another prime (1998961037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999480528 + 999480529.

It is an arithmetic number, because the mean of its divisors is an integer number (999480529).

Almost surely, 2^1998961057 is an apocalyptic number.

It is an amenable number.

1998961057 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998961057 is an equidigital number, since it uses as much as digits as its factorization.

1998961057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1224720, while the sum is 55.

The square root of 1998961057 is about 44709.7423052292. The cubic root of 1998961057 is about 1259.7028477480.

The spelling of 1998961057 in words is "one billion, nine hundred ninety-eight million, nine hundred sixty-one thousand, fifty-seven".