643951460 has 24 divisors (see below), whose sum is σ = 1362626496. Its totient is φ = 255613280.

The previous prime is 643951459. The next prime is 643951471. The reversal of 643951460 is 64159346.

643951460 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×643951460² = 829346965672263200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 120272 + ... + 125511.

It is an arithmetic number, because the mean of its divisors is an integer number (56776104).

Almost surely, 2^643951460 is an apocalyptic number.

It is an amenable number.

643951460 is an abundant number, since it is smaller than the sum of its proper divisors (718675036).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643951460 is a wasteful number, since it uses less digits than its factorization.

643951460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245923 (or 245921 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 38.

The square root of 643951460 is about 25376.1986908993. The cubic root of 643951460 is about 863.5438138917.

The spelling of 643951460 in words is "six hundred forty-three million, nine hundred fifty-one thousand, four hundred sixty".