643033394 has 4 divisors (see below), whose sum is σ = 964550094. Its totient is φ = 321516696.

The previous prime is 643033387. The next prime is 643033409. The reversal of 643033394 is 493330346.

643033394 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 378808369 + 264225025 = 19463^2 + 16255^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160758347 + ... + 160758350.

Almost surely, 2^643033394 is an apocalyptic number.

643033394 is a deficient number, since it is larger than the sum of its proper divisors (321516700).

643033394 is a wasteful number, since it uses less digits than its factorization.

643033394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321516699.

The product of its (nonzero) digits is 69984, while the sum is 35.

The square root of 643033394 is about 25358.1031230650. The cubic root of 643033394 is about 863.1332408817.

The spelling of 643033394 in words is "six hundred forty-three million, thirty-three thousand, three hundred ninety-four".