775409989 has 2 divisors, whose sum is σ = 775409990. Its totient is φ = 775409988.

The previous prime is 775409959. The next prime is 775410011. The reversal of 775409989 is 989904577.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 439237764 + 336172225 = 20958^2 + 18335^2 .

It is a cyclic number.

It is not a de Polignac number, because 775409989 - 2¹⁵ = 775377221 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (775409939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 387704994 + 387704995.

It is an arithmetic number, because the mean of its divisors is an integer number (387704995).

Almost surely, 2^775409989 is an apocalyptic number.

It is an amenable number.

775409989 is a deficient number, since it is larger than the sum of its proper divisors (1).

775409989 is an equidigital number, since it uses as much as digits as its factorization.

775409989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5715360, while the sum is 58.

The square root of 775409989 is about 27846.1844603529. The cubic root of 775409989 is about 918.7072221340.

The spelling of 775409989 in words is "seven hundred seventy-five million, four hundred nine thousand, nine hundred eighty-nine".