1542123509 has 2 divisors, whose sum is σ = 1542123510. Its totient is φ = 1542123508.

The previous prime is 1542123403. The next prime is 1542123521. The reversal of 1542123509 is 9053212451.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 787083025 + 755040484 = 28055^2 + 27478^2 .

It is a cyclic number.

It is not a de Polignac number, because 1542123509 - 2¹² = 1542119413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1542122509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 771061754 + 771061755.

It is an arithmetic number, because the mean of its divisors is an integer number (771061755).

Almost surely, 2^1542123509 is an apocalyptic number.

It is an amenable number.

1542123509 is a deficient number, since it is larger than the sum of its proper divisors (1).

1542123509 is an equidigital number, since it uses as much as digits as its factorization.

1542123509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 1542123509 is about 39269.8804301719. The cubic root of 1542123509 is about 1155.3308919954.

The spelling of 1542123509 in words is "one billion, five hundred forty-two million, one hundred twenty-three thousand, five hundred nine".