643780425 has 48 divisors (see below), whose sum is σ = 1105554240. Its totient is φ = 330167040.

The previous prime is 643780411. The next prime is 643780451. The reversal of 643780425 is 524087346.

It is a happy number.

It is not a de Polignac number, because 643780425 - 2⁸ = 643780169 is a prime.

It is a super-2 number, since 2×643780425² = 828906471226361250, which contains 22 as substring.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 754299 + ... + 755151.

It is an arithmetic number, because the mean of its divisors is an integer number (23032380).

Almost surely, 2^643780425 is an apocalyptic number.

It is an amenable number.

643780425 is a deficient number, since it is larger than the sum of its proper divisors (461773815).

643780425 is a wasteful number, since it uses less digits than its factorization.

643780425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1242 (or 1237 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 39.

The square root of 643780425 is about 25372.8284785122. The cubic root of 643780425 is about 863.4673540427.

The spelling of 643780425 in words is "six hundred forty-three million, seven hundred eighty thousand, four hundred twenty-five".