1287021497 has 2 divisors, whose sum is σ = 1287021498. Its totient is φ = 1287021496.

The previous prime is 1287021427. The next prime is 1287021517. The reversal of 1287021497 is 7941207821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 952277881 + 334743616 = 30859^2 + 18296^2 .

It is a cyclic number.

It is not a de Polignac number, because 1287021497 - 2¹⁰ = 1287020473 is a prime.

It is not a weakly prime, because it can be changed into another prime (1287021427) 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, 643510748 + 643510749.

It is an arithmetic number, because the mean of its divisors is an integer number (643510749).

Almost surely, 2^1287021497 is an apocalyptic number.

It is an amenable number.

1287021497 is a deficient number, since it is larger than the sum of its proper divisors (1).

1287021497 is an equidigital number, since it uses as much as digits as its factorization.

1287021497 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56448, while the sum is 41.

The square root of 1287021497 is about 35875.0818396279. The cubic root of 1287021497 is about 1087.7487685967.

The spelling of 1287021497 in words is "one billion, two hundred eighty-seven million, twenty-one thousand, four hundred ninety-seven".