643369407 has 4 divisors (see below), whose sum is σ = 857825880. Its totient is φ = 428912936.

The previous prime is 643369373. The next prime is 643369421. The reversal of 643369407 is 704963346.

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

It is a cyclic number.

It is not a de Polignac number, because 643369407 - 2⁸ = 643369151 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643369457) 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, 107228232 + ... + 107228237.

It is an arithmetic number, because the mean of its divisors is an integer number (214456470).

Almost surely, 2^643369407 is an apocalyptic number.

643369407 is a deficient number, since it is larger than the sum of its proper divisors (214456473).

643369407 is a wasteful number, since it uses less digits than its factorization.

643369407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214456472.

The product of its (nonzero) digits is 326592, while the sum is 42.

The square root of 643369407 is about 25364.7276153323. The cubic root of 643369407 is about 863.2835562932.

The spelling of 643369407 in words is "six hundred forty-three million, three hundred sixty-nine thousand, four hundred seven".