57121006661 has 2 divisors, whose sum is σ = 57121006662. Its totient is φ = 57121006660.

The previous prime is 57121006633. The next prime is 57121006669. The reversal of 57121006661 is 16660012175.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56646856036 + 474150625 = 238006^2 + 21775^2 .

It is a cyclic number.

It is not a de Polignac number, because 57121006661 - 2⁶ = 57121006597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (57121006669) 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, 28560503330 + 28560503331.

It is an arithmetic number, because the mean of its divisors is an integer number (28560503331).

Almost surely, 2^57121006661 is an apocalyptic number.

It is an amenable number.

57121006661 is a deficient number, since it is larger than the sum of its proper divisors (1).

57121006661 is an equidigital number, since it uses as much as digits as its factorization.

57121006661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 35.

The spelling of 57121006661 in words is "fifty-seven billion, one hundred twenty-one million, six thousand, six hundred sixty-one".