643456942 has 8 divisors (see below), whose sum is σ = 972230976. Its totient is φ = 319379952.

The previous prime is 643456939. The next prime is 643456943. The reversal of 643456942 is 249654346.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643456943) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1173918 + ... + 1174465.

It is an arithmetic number, because the mean of its divisors is an integer number (121528872).

Almost surely, 2^643456942 is an apocalyptic number.

643456942 is a deficient number, since it is larger than the sum of its proper divisors (328774034).

643456942 is a wasteful number, since it uses less digits than its factorization.

643456942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2348522.

The product of its digits is 622080, while the sum is 43.

The square root of 643456942 is about 25366.4530827627. The cubic root of 643456942 is about 863.3227064809.

The spelling of 643456942 in words is "six hundred forty-three million, four hundred fifty-six thousand, nine hundred forty-two".