1311566989 has 2 divisors, whose sum is σ = 1311566990. Its totient is φ = 1311566988.

The previous prime is 1311566953. The next prime is 1311567077. The reversal of 1311566989 is 9896651131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1202008900 + 109558089 = 34670^2 + 10467^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311566989 - 2¹³ = 1311558797 is a prime.

It is a super-2 number, since 2×1311566989² = 3440415933269052242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1311566909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655783494 + 655783495.

It is an arithmetic number, because the mean of its divisors is an integer number (655783495).

Almost surely, 2^1311566989 is an apocalyptic number.

It is an amenable number.

1311566989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311566989 is an equidigital number, since it uses as much as digits as its factorization.

1311566989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 349920, while the sum is 49.

The square root of 1311566989 is about 36215.5628010942. The cubic root of 1311566989 is about 1094.6202860420.

The spelling of 1311566989 in words is "one billion, three hundred eleven million, five hundred sixty-six thousand, nine hundred eighty-nine".