646837489 has 9 divisors (see below), whose sum is σ = 670676097. Its totient is φ = 623820624.

The previous prime is 646837447. The next prime is 646837507. The reversal of 646837489 is 984738646.

The square root of 646837489 is 25433.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 98903025 + 547934464 = 9945^2 + 23408^2 .

It is not a de Polignac number, because 646837489 - 2⁹ = 646836977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646837409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 737119 + ... + 737995.

Almost surely, 2^646837489 is an apocalyptic number.

646837489 is the 25433-rd square number.

646837489 is the 12717-th centered octagonal number.

It is an amenable number.

646837489 is a deficient number, since it is larger than the sum of its proper divisors (23838608).

646837489 is an frugal number, since it uses more digits than its factorization.

646837489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1812 (or 906 counting only the distinct ones).

The product of its digits is 6967296, while the sum is 55.

The cubic root of 646837489 is about 864.8319537230.

The spelling of 646837489 in words is "six hundred forty-six million, eight hundred thirty-seven thousand, four hundred eighty-nine".