705509989 has 2 divisors, whose sum is σ = 705509990. Its totient is φ = 705509988.

The previous prime is 705509923. The next prime is 705510041. The reversal of 705509989 is 989905507.

It is an a-pointer prime, because the next prime (705510041) can be obtained adding 705509989 to its sum of digits (52).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 462680100 + 242829889 = 21510^2 + 15583^2 .

It is an emirp because it is prime and its reverse (989905507) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 705509989 - 2²¹ = 703412837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (705509789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 352754994 + 352754995.

It is an arithmetic number, because the mean of its divisors is an integer number (352754995).

Almost surely, 2^705509989 is an apocalyptic number.

It is an amenable number.

705509989 is a deficient number, since it is larger than the sum of its proper divisors (1).

705509989 is an equidigital number, since it uses as much as digits as its factorization.

705509989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1020600, while the sum is 52.

The square root of 705509989 is about 26561.4380070056. The cubic root of 705509989 is about 890.2276020179.

The spelling of 705509989 in words is "seven hundred five million, five hundred nine thousand, nine hundred eighty-nine".