1951661165057 has 2 divisors, whose sum is σ = 1951661165058. Its totient is φ = 1951661165056.

The previous prime is 1951661165039. The next prime is 1951661165177. The reversal of 1951661165057 is 7505611661591.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1947576549136 + 4084615921 = 1395556^2 + 63911^2 .

It is a cyclic number.

It is not a de Polignac number, because 1951661165057 - 2⁶ = 1951661164993 is a prime.

It is not a weakly prime, because it can be changed into another prime (1951661165017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 975830582528 + 975830582529.

It is an arithmetic number, because the mean of its divisors is an integer number (975830582529).

Almost surely, 2^{1951661165057} is an apocalyptic number.

It is an amenable number.

1951661165057 is a deficient number, since it is larger than the sum of its proper divisors (1).

1951661165057 is an equidigital number, since it uses as much as digits as its factorization.

1951661165057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1701000, while the sum is 53.

The spelling of 1951661165057 in words is "one trillion, nine hundred fifty-one billion, six hundred sixty-one million, one hundred sixty-five thousand, fifty-seven".