1321787123 has 2 divisors, whose sum is σ = 1321787124. Its totient is φ = 1321787122.

The previous prime is 1321787119. The next prime is 1321787147. The reversal of 1321787123 is 3217871231.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1321787123 - 2² = 1321787119 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (1321787153) 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, 660893561 + 660893562.

It is an arithmetic number, because the mean of its divisors is an integer number (660893562).

Almost surely, 2^1321787123 is an apocalyptic number.

1321787123 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321787123 is an equidigital number, since it uses as much as digits as its factorization.

1321787123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14112, while the sum is 35.

The square root of 1321787123 is about 36356.3904011386. The cubic root of 1321787123 is about 1097.4561389549.

The spelling of 1321787123 in words is "one billion, three hundred twenty-one million, seven hundred eighty-seven thousand, one hundred twenty-three".