1557750612221 has 2 divisors, whose sum is σ = 1557750612222. Its totient is φ = 1557750612220.

The previous prime is 1557750612169. The next prime is 1557750612283. The reversal of 1557750612221 is 1222160577551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1527522964900 + 30227647321 = 1235930^2 + 173861^2 .

It is a cyclic number.

It is not a de Polignac number, because 1557750612221 - 2¹⁴ = 1557750595837 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1557750692221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 778875306110 + 778875306111.

It is an arithmetic number, because the mean of its divisors is an integer number (778875306111).

Almost surely, 2^{1557750612221} is an apocalyptic number.

It is an amenable number.

1557750612221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1557750612221 is an equidigital number, since it uses as much as digits as its factorization.

1557750612221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 294000, while the sum is 44.

The spelling of 1557750612221 in words is "one trillion, five hundred fifty-seven billion, seven hundred fifty million, six hundred twelve thousand, two hundred twenty-one".