1538788991 has 2 divisors, whose sum is σ = 1538788992. Its totient is φ = 1538788990.

The previous prime is 1538788963. The next prime is 1538789027. The reversal of 1538788991 is 1998878351.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1538788991 - 2²⁶ = 1471680127 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1538788991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1538788931) 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, 769394495 + 769394496.

It is an arithmetic number, because the mean of its divisors is an integer number (769394496).

Almost surely, 2^1538788991 is an apocalyptic number.

1538788991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1538788991 is an equidigital number, since it uses as much as digits as its factorization.

1538788991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4354560, while the sum is 59.

The square root of 1538788991 is about 39227.4010227545. The cubic root of 1538788991 is about 1154.4975709950.

The spelling of 1538788991 in words is "one billion, five hundred thirty-eight million, seven hundred eighty-eight thousand, nine hundred ninety-one".