1555020255409 has 2 divisors, whose sum is σ = 1555020255410. Its totient is φ = 1555020255408.

The previous prime is 1555020255367. The next prime is 1555020255449. The reversal of 1555020255409 is 9045520205551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1024453695409 + 530566560000 = 1012153^2 + 728400^2 .

It is a cyclic number.

It is not a de Polignac number, because 1555020255409 - 2⁹ = 1555020254897 is a prime.

It is not a weakly prime, because it can be changed into another prime (1555020255449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 777510127704 + 777510127705.

It is an arithmetic number, because the mean of its divisors is an integer number (777510127705).

Almost surely, 2^{1555020255409} is an apocalyptic number.

It is an amenable number.

1555020255409 is a deficient number, since it is larger than the sum of its proper divisors (1).

1555020255409 is an equidigital number, since it uses as much as digits as its factorization.

1555020255409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 450000, while the sum is 43.

The spelling of 1555020255409 in words is "one trillion, five hundred fifty-five billion, twenty million, two hundred fifty-five thousand, four hundred nine".