1239986689 has 2 divisors, whose sum is σ = 1239986690. Its totient is φ = 1239986688.

The previous prime is 1239986651. The next prime is 1239986719. The reversal of 1239986689 is 9866899321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 929945025 + 310041664 = 30495^2 + 17608^2 .

It is a cyclic number.

It is not a de Polignac number, because 1239986689 - 2¹³ = 1239978497 is a prime.

It is not a weakly prime, because it can be changed into another prime (1239986389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 619993344 + 619993345.

It is an arithmetic number, because the mean of its divisors is an integer number (619993345).

Almost surely, 2^1239986689 is an apocalyptic number.

It is an amenable number.

1239986689 is a deficient number, since it is larger than the sum of its proper divisors (1).

1239986689 is an equidigital number, since it uses as much as digits as its factorization.

1239986689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10077696, while the sum is 61.

The square root of 1239986689 is about 35213.4447193114. Note that the first 3 decimals coincide. The cubic root of 1239986689 is about 1074.3332267546. Note that the first 3 decimals are identical.

The spelling of 1239986689 in words is "one billion, two hundred thirty-nine million, nine hundred eighty-six thousand, six hundred eighty-nine".