642763969 has 2 divisors, whose sum is σ = 642763970. Its totient is φ = 642763968.

The previous prime is 642763949. The next prime is 642763973. The reversal of 642763969 is 969367246.

642763969 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 634284225 + 8479744 = 25185^2 + 2912^2 .

It is a cyclic number.

It is not a de Polignac number, because 642763969 - 2¹³ = 642755777 is a prime.

It is a super-2 number, since 2×642763969² = 826291039689265922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (642763949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321381984 + 321381985.

It is an arithmetic number, because the mean of its divisors is an integer number (321381985).

Almost surely, 2^642763969 is an apocalyptic number.

It is an amenable number.

642763969 is a deficient number, since it is larger than the sum of its proper divisors (1).

642763969 is an equidigital number, since it uses as much as digits as its factorization.

642763969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2939328, while the sum is 52.

The square root of 642763969 is about 25352.7901620315. The cubic root of 642763969 is about 863.0126757800.

The spelling of 642763969 in words is "six hundred forty-two million, seven hundred sixty-three thousand, nine hundred sixty-nine".