643507942 has 32 divisors (see below), whose sum is σ = 1211457024. Its totient is φ = 249048000.

The previous prime is 643507937. The next prime is 643507967. The reversal of 643507942 is 249705346.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 643507895 and 643507904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9418 + ... + 37090.

It is an arithmetic number, because the mean of its divisors is an integer number (37858032).

Almost surely, 2^643507942 is an apocalyptic number.

643507942 is a deficient number, since it is larger than the sum of its proper divisors (567949082).

643507942 is a wasteful number, since it uses less digits than its factorization.

643507942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27844.

The product of its (nonzero) digits is 181440, while the sum is 40.

The square root of 643507942 is about 25367.4583275503. The cubic root of 643507942 is about 863.3455146866.

The spelling of 643507942 in words is "six hundred forty-three million, five hundred seven thousand, nine hundred forty-two".