1555132661 has 2 divisors, whose sum is σ = 1555132662. Its totient is φ = 1555132660.

The previous prime is 1555132591. The next prime is 1555132673. The reversal of 1555132661 is 1662315551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1068047761 + 487084900 = 32681^2 + 22070^2 .

It is a cyclic number.

It is not a de Polignac number, because 1555132661 - 2¹⁸ = 1554870517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1555134661) 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, 777566330 + 777566331.

It is an arithmetic number, because the mean of its divisors is an integer number (777566331).

Almost surely, 2^1555132661 is an apocalyptic number.

It is an amenable number.

1555132661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1555132661 is an equidigital number, since it uses as much as digits as its factorization.

1555132661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27000, while the sum is 35.

The square root of 1555132661 is about 39435.1703559145. The cubic root of 1555132661 is about 1158.5705392973.

The spelling of 1555132661 in words is "one billion, five hundred fifty-five million, one hundred thirty-two thousand, six hundred sixty-one".