643703445 has 72 divisors (see below), whose sum is σ = 1415962080. Its totient is φ = 267503040.

The previous prime is 643703407. The next prime is 643703471. The reversal of 643703445 is 544307346.

It is a happy number.

643703445 is a `hidden beast` number, since 643 + 7 + 0 + 3 + 4 + 4 + 5 = 666.

It is not a de Polignac number, because 643703445 - 2⁶ = 643703381 is a prime.

It is a super-3 number, since 3×643703445³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 10986 + ... + 37524.

It is an arithmetic number, because the mean of its divisors is an integer number (19666140).

Almost surely, 2^643703445 is an apocalyptic number.

It is an amenable number.

643703445 is an abundant number, since it is smaller than the sum of its proper divisors (772258635).

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

643703445 is a wasteful number, since it uses less digits than its factorization.

643703445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26575 (or 26565 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 36.

The square root of 643703445 is about 25371.3114560521. The cubic root of 643703445 is about 863.4329363210.

The spelling of 643703445 in words is "six hundred forty-three million, seven hundred three thousand, four hundred forty-five".