1557013352821 has 2 divisors, whose sum is σ = 1557013352822. Its totient is φ = 1557013352820.

The previous prime is 1557013352771. The next prime is 1557013352831. The reversal of 1557013352821 is 1282533107551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1373375391921 + 183637960900 = 1171911^2 + 428530^2 .

It is a cyclic number.

It is not a de Polignac number, because 1557013352821 - 2³¹ = 1554865869173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1557013352831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 778506676410 + 778506676411.

It is an arithmetic number, because the mean of its divisors is an integer number (778506676411).

Almost surely, 2^{1557013352821} is an apocalyptic number.

It is an amenable number.

1557013352821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1557013352821 is an equidigital number, since it uses as much as digits as its factorization.

1557013352821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 252000, while the sum is 43.

The spelling of 1557013352821 in words is "one trillion, five hundred fifty-seven billion, thirteen million, three hundred fifty-two thousand, eight hundred twenty-one".