1287650993 has 2 divisors, whose sum is σ = 1287650994. Its totient is φ = 1287650992.

The previous prime is 1287650981. The next prime is 1287651017. The reversal of 1287650993 is 3990567821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1285724449 + 1926544 = 35857^2 + 1388^2 .

It is an emirp because it is prime and its reverse (3990567821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1287650993 - 2¹² = 1287646897 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1287650393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 643825496 + 643825497.

It is an arithmetic number, because the mean of its divisors is an integer number (643825497).

Almost surely, 2^1287650993 is an apocalyptic number.

It is an amenable number.

1287650993 is a deficient number, since it is larger than the sum of its proper divisors (1).

1287650993 is an equidigital number, since it uses as much as digits as its factorization.

1287650993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 816480, while the sum is 50.

The square root of 1287650993 is about 35883.8542104942. The cubic root of 1287650993 is about 1087.9260828824.

The spelling of 1287650993 in words is "one billion, two hundred eighty-seven million, six hundred fifty thousand, nine hundred ninety-three".