1557061102391 has 2 divisors, whose sum is σ = 1557061102392. Its totient is φ = 1557061102390.

The previous prime is 1557061102309. The next prime is 1557061102397. The reversal of 1557061102391 is 1932011607551.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1557061102391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1557061102397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 778530551195 + 778530551196.

It is an arithmetic number, because the mean of its divisors is an integer number (778530551196).

Almost surely, 2^{1557061102391} is an apocalyptic number.

1557061102391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1557061102391 is an equidigital number, since it uses as much as digits as its factorization.

1557061102391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56700, while the sum is 41.

The spelling of 1557061102391 in words is "one trillion, five hundred fifty-seven billion, sixty-one million, one hundred two thousand, three hundred ninety-one".