643373667 has 6 divisors (see below), whose sum is σ = 929317532. Its totient is φ = 428915772.

The previous prime is 643373663. The next prime is 643373677. The reversal of 643373667 is 766373346.

It is not a de Polignac number, because 643373667 - 2² = 643373663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643373663) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35742973 + ... + 35742990.

Almost surely, 2^643373667 is an apocalyptic number.

643373667 is a deficient number, since it is larger than the sum of its proper divisors (285943865).

643373667 is a wasteful number, since it uses less digits than its factorization.

643373667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71485969 (or 71485966 counting only the distinct ones).

The product of its digits is 1143072, while the sum is 45.

The square root of 643373667 is about 25364.8115900749. The cubic root of 643373667 is about 863.2854616681.

The spelling of 643373667 in words is "six hundred forty-three million, three hundred seventy-three thousand, six hundred sixty-seven".